Freitag, 18. Dezember 2009

Laptop Computer Repair Tips
































• • • Laptop Computer Repair Tips

• MAJOR PARTS OF A LAPTOP COMPUTER

• Laptop Keyboard
• Laptop Screen
• Laptop Hard Disk
• Laptop Battery
• Laptop Mother Board
• Laptop System RAM
• Laptop Power Pack







Guys, don’t undertake laptop computer repair without reading this first. I’ll guide you away from making costly mistakes that could render your laptop computer useless.

First of all have a good understanding of what it is you need to do and what you might need in the way of tools. A big mistake people make is to sit down with a part and their laptop and use whatever they have around to open up the laptop and replace the part.

What you should try and have before you start..
• 1 x Philips Head Screwdriver type 0
• 1 x Philips Head Screwdriver type 1
• Tweezers ( long nose )
• ESD mat or grounded ESD wrist strap (Electrostatic Discharge)
• Needle nose pliers
• A Teflon wedge or splade

Also take a look at the environment you are going to do your laptop computer repair in, static electricity can ruin your day and you won’t even know it..

Back up your laptop's hard drive just in case you do something you shouldn’t have. Avoid doing your laptop computer repair in a carpeted room, use the kitchen or garage.

Keep in mind that if you are playing with the LCD the backlight inverter can give you a nasty shock if the unit is powered, switch the laptop off and unplug it, you should also remove the laptop's battery and hard drive.

I understand that most people won’t have any anti-static gear like wrist straps and so on but if you are going to be doing some laptop computer repair on a regular basis, it may be worth while getting some, although the laptop you have may be a cheap one there is no point killing it off and dumping it in the trash.








Some points to remember when undertaking laptop computer repairs.
• Don’t disassemble a machine if it doesn’t need it.
• Use the right tools.
• Try to do it in a clean environment.
• Test the machine properly beforehand
• Keep any parts you remove in a safe place.
• Keep the screws with the parts they have been taken from.
• Put the right size screws back into parts when it's time to reassemble it.
• Observe how connectors work before disconnecting them.
• Make notes for yourself if you need to as you pull apart the machine.
• Check all cables and connectors are fastened as you go along.
• Try not to use screwdrivers to lever or remove plastic parts.
• If a part won't budge look for hidden screws or a screw you may have missed.
• TAKE YOUR TIME.


Note: Some laptops have the screw holes marked with screw types and sizes. Some use symbols to indicate screw types. Take notice of what screws come out of where.






• •













• Laptop Keyboard Repair

Laptop keyboard repair is one of the more common jobs performed on laptops, it's also one of the easier repairs to carry out providing the following hasn't happened.

A spill of anything but water on a keyboard will 9 times out of 10 leave you in a situation that involves replacing the keyboard all together.

Keyboards are manufactured in such a way that leaves little to no room to clean out messy spills.


Basically any liquid containing sugar (soft drinks, beer, wine, coffee or tea) are bad news...

A couple of laptop keyboard repair do’s and don’ts in the event of a spill.


DON’T panic. Panic makes us do stupid things, think before you react.

DON’T use a hairdryer to dry out a spill...melted keys are hard to type with.

DON’T tilt the machine upside down or on its side (if you do feel the need it's better to tilt it to the side that houses the CDROM as the CDROM area inside the machine has less components on it than the main board).

DO switch the machine off immediately and resist switching it back on until you're certain the spill has dried. Survey the damage after you've dried it out. At this point you could remove the keyboard and try the machine using an external keyboard to see if anything else has been affected.


• This diagram shows what a basic keyboard looks like; the ribbon cable which connects the keyboard to the motherboard is indicated by the red arrow.


The ribbon cable can also be located on the front edge of the keyboard depending on the age and model of the laptop you have.
Note the keyboard holder (thin strip of plastic) that sits on the top edge of the laptop keyboard needs to be removed to get access to the screws holding the keyboard down.
Most of the current laptop keyboards are like the diagram below.


Traditionally a spill will kill a keyboard or at best at least some function will be lost. I have only ever been successful with a laptop keyboard repair that involved a water spill, anything else normally results in a tragic loss and putting your old faithful keyboard to rest.. RIP.



• How to replace a laptop keyboard
• Keyboard removal is relatively simple, most keyboards are held in place with a couple of screws, and in some models, also a couple of screws that may need to be removed from the base of the unit. A quick call to your local authorized laptop computer repairer should help to determine what screws need to be removed (if they know their stuff).

The keyboard connector is something that needs a little care when unplugging, if you are too heavy handed and damage the connector in any way you may even damage the main board also which can cause a world of pain... Be careful.

See below for the most commonly used connector.

• In order to release the keyboard ribbon cable ease the connector edge upwards only about 2 or 3 millimeters, the ribbon should now slip out with ease. The refitting of the keyboard once cleaned or replaced is just done in reverse.
• Broken off some keys??
• Whoops, these are a difficult one to fix and once again often end in having to replace the keyboard entirely. Some very small plastic mounting arms hold the keys in place and are often broken, either that or the little clips that the mounting arms click into break. It's handy to have or get a hold of an old keyboard of the same type in order to poach the parts you need.

You may need some tweezers and a steady hand to fix these. The best thing I can suggest is to gently remove one of the other keys to see exactly how the mounting arms sit, once you have an idea of how it should look grab those tweezers and be patient, it may take some time.

We will soon have some detailed photos showing how these are assembled, until then remember to be patient and gentle.

If you seek professional advice regarding your laptop keyboard repair, the repairer will probably try to sell you a new keyboard complete with hefty labour charge to fix this for you. With the tips we have given you here, you can do it your self.
• Laptop Screen Repair




• Backlight and Inverter problems:

Well people, laptop screen repair will be something you will no doubt need info on at some point in your laptop's life... The symptoms are that the laptop display panel will flicker and then appear to switch off, but if you look closely you can still see a very faint image on the panel, almost like peering through the dark, this is because the backlight isn't lit.

Inverter boards have been an issue in a lot of makes and models of laptops – this is a very common fault. The inverter board loses proper connection causing the backlight to flicker or just simply fails altogether.

A little info in what we mean when we say 'Back Light'. Your screen has a fluorescent tube inside it which is just like your normal household tube except for its size; it's about 1/10 of the size. The tube is attached to a small circuit board via a cable, the circuit board acts like the starter in your household variety. This circuit board is called an 'Inverter or FL Inverter’; the inverter provides regulated power to the fluorescent tube which lights up the screen.

If the Inverter fails then you appear to have no display, yes and no, the screen is still displaying the image but without light from the tube it only appears ever so faintly.

A lot of repairers will make the assumption that the LCD has failed and tell you about the enormous cost involved in a laptop screen repair to resurrect your beloved laptop, if you're unlucky this may be the case. Some repairers may even tell you it’s the main board because the video card has failed, they'll tell you that your laptop screen repair will involve replacing expensive circuit cards... Rubbish.

One way of verifying this for yourself is to connect an external monitor to your laptop's VGA port and flipping to dual display or external only display, if you get an image then you have narrowed it down to the inverter or the LCD panel.

The Inverter is a small PCB that is generally located in the LCD cover assembly close by the LCD itself. In most cases it can be found either screwed to the case underneath or along side the LCD panel.

Please see diagram below.


• You will need to remove the mask assembly which is the plastic outer border around the screen. If you are the type to be a little heavy handed and impatient, then this is not the task for you. Working around an expensive LCD panel is only for people who have the utmost confidence in what they're doing, the average LCD panel makes up 50% of the overall cost of a laptop and in some cases replacement costs are huge. (Be patient and use minimal force)



Be sure to remove all the screws holding the mask in place, normally expect to see approximately 4-6 screws. In some machines there will be only 2, the mask is also fixed in by snapping type clips that make it fit to the rear cover assembly.

Once you’ve taken that off, you'll have exposed the LCD and inverter which will both be connected to the LCD harness or wire loom that connects them both to the main board.


1. Connects to the rear of the LCD panel.

2. Connects to the Inverter board or FL inverter.

3. Connects to the main board.

Disconnect the inverter from the harness and from the LCD (the inverter will have a cable plugged into both ends of it) now.. here’s the thing. In a lot of cases your laptop screen repair is just a case of cleaning the inverter pins with some contact cleaner and this will fix the issue for a good while.

The reason is that the pins develop a film on them and lose good connection with the plug that is plugged into them, it’s a good idea to clean the harness plug as well.
If you want to achieve a more permanent fix you will need to apply some Glue (Threebond 1530B) to the end that the harness plugs into (plug number 2, see left image), this will prevent the dirt film forming again on the pins over time.

Once this is done the unit can be reassembled and it should be OK. If you have a faulty inverter that needs replacing the cost will vary from place to place, but study our laptop screen repair guide and use the info to save yourself some money.

















• Need To Repair Your Laptop Hinge
• If you need to repair your laptop hinge it will usually be because your screen is loose and refuses to remain upright or when the hinges themselves crack or break under the repetitive strain of opening and closing.

This is often caused by the hinges themselves being too rigid or missing base screws. So check your base screws are in place and screwed in securely. When base screws are missing, particularly the main structural screws located in the corners of the base assembly, the load from the hinges isn’t sufficiently transferred across the hinge and base assembly, hence the hinges will have to bear the load and wear prematurely.

A lot of hinges are made of cast metal leaving no room for flexing and bending. The image below shows the cover assembly from a Toshiba Satellite A10 just to give you an idea of what it looks like inside.

The arrow indicates where the problem will normally occur, the teeth on the fixed arm will shear off over time making the screen very loose, these cannot be repaired and involve changing the cover assembly. This is probably the best way to do it as instead of a laptop hinge repair, you get a whole new cover and your laptop ends up looking like a new one.
Satellite A10 cover assy.

Cover assemblies are not expensive, just ensure you get the right cover that matches the type of LCD you have. Not all covers are exactly the same because laptop manufacturers don’t always use the same type or model of screen during the assembly of new laptops. The differences will be minor but they can prevent you fitting your LCD back into the new cover mainly due to the placement of screw holes and mountings.

The next 2 images show the result of a laptop which was missing its 2 main structural screws from the base assembly.







Toshiba Satellite 2600, missing base assy. screws and damaged hinges and cover.

There is no real cost effective way to repair your laptop hinge and if it was a system I was working on I would advise the owner to replace the cover and base screws, I would have to simply say no if I was requested to attempt a plastics repair or modification to something like this. It's too time consuming and would end up costing more in labour time that it would to replace the entire cover.






• Laptop overheating? Laptop Overheating Issues:
Does your laptop shutdown at random? Does it slow down during heavy operations? Do you need to wait 10 min. before you can start it up again? These are all the symptoms of a laptop overheating problem in or around the cooling system.

What needs to be remembered is that a lot of the current laptops on the market today are running specifications that traditionally were reserved for desktops. Some even contain desktop CPU’s and a kick ass cooling system to match. Take a look at the cooling modules in some of the current Toshiba notebooks.

Anyhow, in order for these CPU’s to perform they have to be kept as cool as possible so manufacturers like Toshiba, Compaq/HP and the like struggle with the limited space and power to do this, hence they have had some laptop overheating issues.

If your laptop does show some of the symptoms mentioned before here’s what you can do..

On the under side of a lot of the machines you can gain access to the CPU/cooling module compartment, be warned – when tinkering around near the CPU, electro static discharge may be your worst nightmare - be careful to control ESD. Once you have located where the fan is you will be able to see quite clearly if this is your issue.. take a look below.



1: Heat sink
2: Fan

The heat sink runs off to the right of this picture and sits on the CPU, you can see the copper pipe running to the CPU here (1).

The fan and the heat sink have a small gap in between them, this is where dust will be sucked into and will accumulate.


Dust build up inside a Toshiba Satellite A10

You can use a soft paint brush safely enough here to loosen all the dust and then use a vacuum with a brush attachment to remove it. If you're game you can take the fan out (2 screws to remove) and give it a good clean out. This isn’t always so easy, on other models of notebooks the fan or fans are only accessible by removing the main board, not a job for a novice.


Dust build up inside a Toshiba Satellite A10 with the fan removed.


Arrows mark what should be cleaned out before re-assembly.

Once all the dust and lint is removed, re-assemble your machine. This procedure is something that should be done periodically to ensure that your laptop overheating issues will be a thing of the past.
• Hard drive replacement for your laptop
• A hard drive replacement for your laptop will be a common issue that will continue to plague the laptop owners and operators of the world until the laptop hard drive technology moves to solid state drives, as long as there are moving parts inside that hard disk we will have to put up with head crashes and bad sectors. That’s not to say that any new technology won't have a whole new array of unseen or even unheard of errors and problems.. not giving you a lot of confidence in your data storage am I.

I have one word of advice.. BACKUPS.

OK, back to the info…

A hard drive replacement for your laptop is generally one of the easier jobs to do yourself unless you have one of the makes and models of laptop that doesn’t provide easy access to the hard disk, hiding it away under the palm rest or worse still mounting it to the main board. Luckily there are not a lot of these and most of the laptop makers now recognize the need to have access to the drive for various reasons.

Replacing a drive is simple.. generally you can remove 1 screw from the HDD cavity or enclosure and the drive can be removed by sliding it out.

See images below.



HDD enclosure on a Toshiba Satellite 6100.


Once the hard disk is removed it will have some sort of aluminum case or frame that it screws into which will need to be removed and fitted to the new drive. This step is essential to your laptop hard drive repair or the drive won't slide back in properly and possibly bend the pins if you try and insert it.. this is bad.





• HDD with bracket removed on a Toshiba Satellite 6100.



HDD with aluminium bracket on a Toshiba Tecra 9000.

Some drives have a HDD connector cover on the pins which also needs to be removed and put on the new drive. See below.



HDD with connector on a Toshiba Tecra 9000.

Be gentle when re-inserting the new drive, damage to the pins can be a painful affair. If you insert the drive and the laptop doesn’t boot try removing it and re-inserting as the pins may be misaligned.

Keep in mind too that new laptop hard drives are shipped un-partitioned and not formatted just the same as normal IDE drives, hopefully you still have your recovery CD’s that came with your laptop, if not don’t worry you can use a Windows CD to rebuild your laptop from scratch and then access the internet at some stage to download drivers specific to your laptop (generally available from the laptop manufacturer's website).

If you consider yourself a novice when it comes to installing operating systems then my advice is to have somebody who knows how do it for you, this will save you a lot of time and frustration.

Here are some Compaq images I found also, there’s not a lot of difference between makes so the basic concept is the same.

HDD removal on a Compaq EVO.




HDD casing on a Compaq EVO.

As we said earlier, a hard drive replacement for your laptop isn't particularly hard to do, it's more about whether you can save any data on your hard drive if it fails completely.
















• Laptop Data Recovery
• Laptop data recovery may be something you need to undertake if your laptop won't boot from the drive or makes a loud ticking or grinding noise, not a lot can be done apart from replacing the laptop hard drive entirely.

Your options here are limited and generally involve attempting some data recovery if you need to retrieve something off the faulty drive.

Data recovery can also be a limited endeavor if you want to keep the cost down, there are laptop data recovery specialists out there that charge considerable amounts to recover data for you. Your cheaper options are to purchase, loan or steal an external USB drive enclosure or caddy (see images below) to fit your drive to in order to connect it to another PC to see if you can view the contents of the drive.

If you do this and your notebook drive is not detected or viewable when connected to the other PC then the expensive option looks likely to be your only one if you want to recover any data off the drive.







• Need To Repair Your Laptop Battery?

OK, bad news first. There isn't much you can do to repair your laptop battery. There are companies that claim they can do what they call repacking or reconditioning but what you will find is the end result may not be worth the money spent on this service, not to mention that laptop manufacturers don’t recommend the practice.

In fact the manufacturers may void your laptop warranty (if it still has any) if you use a repacked or reconditioned battery. Replacing your battery with a new one is generally the best plan if you want to avoid any issues and extra expenses.

Laptop batteries are often not interchangeable with others due to things like power output and physical dimensions, most of the laptop batteries these days are molded and are a custom fit to a specific model of machine. Take a look at the images below to see what I mean.



• Laptop battery for a Toshiba 7020CT





• Laptop battery for a Toshiba Tecra 9100


• To sum it all up, best practice here if you need to repair your laptop battery because it's not charging is just to replace it with a brand new one and avoid any warranty or safety issues.
• Prolonged battery life through moderation

Batteries live longer if treated in a gentle manner. High charge voltages, excessive charge rate and extreme load conditions have a negative effect on battery life. The longevity is often a direct result of the environmental stresses applied. The following guidelines suggest ways to prolong battery life.

-The time at which the battery stays at 4.20/cell should be as short as possible. Prolonged high voltage promotes corrosion, especially at elevated temperatures. Spinel is less sensitive to high voltage.

-3.92V/cell is the best upper voltage threshold for cobalt-based lithium-ion. Charging batteries to this voltage level has been shown to double cycle life. Lithium-ion systems for defense applications make use of the lower voltage threshold. The negative is a much lower capacity.

-The charge current of Li-ion should be moderate (0.5C for cobalt-based lithium-ion). The lower charge current reduces the time in which the cell resides at 4.20V. A 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage into voltage limit prematurely.

-Do not discharge lithium-ion too deeply. Instead, charge it frequently. Lithium-ion does not have memory problems like nickel-cadmium batteries. No deep discharges are needed for conditioning.

-Do not charge lithium-ion at or below freezing temperature. Although accepting charge, an irreversible plating of metallic lithium will occur that compromises the safety of the pack.
• Not only does a lithium-ion battery live longer with a slower charge rate; moderate discharge rates also help. Figure 5 shows the cycle life as a function of charge and discharge rates. Observe the improved laboratory performance on a charge and discharge rate of 1C compared to 2 and 3C.
• • Figure 5: Longevity of lithium-ion as a function of charge and discharge rates.
A moderate charge and discharge puts less stress on the battery, resulting in a longer cycle life.
• Battery experts agree that the longevity of lithium-ion is shortened by other factors than charge and discharge rates. Even though incremental improvements can be achieved with careful use, our environment and the services required are not always conducive for optimal battery life. In this respect, the battery behaves much like us humans - we cannot always live a life that caters to achieve maximum life span.


Lithium-ion safety concerns (BU5B)

When Sony introduced the first lithium-ion battery in 1991, they knew of the potential safety risks. A recall of the previously released rechargeable metallic lithium battery was a bleak reminder of the discipline one must exercise when dealing with this high energy-dense battery system.

Pioneering work for the lithium battery began in 1912, but is was not until the early 1970's when the first non-rechargeable lithium batteries became commercially available. Attempts to develop rechargeable lithium batteries followed in the eighties. These early models were based on metallic lithium and offered very high energy density. However, inherent instabilities of lithium metal, especially during charging, put a damper on the development. The cell had the potential of a thermal run-away. The temperature would quickly rise to the melting point of the metallic lithium and cause a violent reaction. A large quantity of rechargeable lithium batteries had to be recalled in 1991 after the pack in a cellular phone released hot gases and inflicted burns to a man's face.

Because of the inherent instability of lithium metal, research shifted to a non-metallic lithium battery using lithium ions. Although slightly lower in energy density, the lithium-ion system is safe, providing certain precautions are met when charging and discharging. Today, lithium-ion is one of the most successful and safe battery chemistries available. Two billion cells are produced every year.

Lithium-ion cells with cobalt cathodes hold twice the energy of a nickel-based battery and four-times that of lead acid. Lithium-ion is a low maintenance system, an advantage that most other chemistries cannot claim. There is no memory and the battery does not require scheduled cycling to prolong its life. Nor does lithium-ion have the sulfation problem of lead acid that occurs when the battery is stored without periodic topping charge. Lithium-ion has a low self-discharge and is environmentally friendly. Disposal causes minimal harm.

Long battery runtimes have always been the wish of many consumers. Battery manufacturers responded by packing more active material into a cell and making the electrodes and separator thinner. This enabled a doubling of energy density since lithium-ion was introduced in 1991.

The high energy density comes at a price. Manufacturing methods become more critical the denser the cells become. With a separator thickness of only 20-25µm, any small intrusion of metallic dust particles can have devastating consequences. Appropriate measures will be needed to achieve the mandated safety standard set forth by UL 1642. Whereas a nail penetration test could be tolerated on the older 18650 cell with a capacity of 1.35Ah, today's high-density 2.4Ah cell would become a bomb when performing the same test. UL 1642 does not require nail penetration. Lithium-ion batteries are nearing their theoretical energy density limit and battery manufacturers are beginning to focus on improving manufacturing methods and increasing safety.

Recall of lithium-ion batteries

With the high usage of lithium-ion in cell phones, digital cameras and laptops, there are bound to be issues. A one-in-200,000 failure rate triggered a recall of almost six million lithium-ion packs used in laptops manufactured by Dell and Apple. Heat related battery failures are taken very seriously and manufacturers chose a conservative approach. The decision to replace the batteries puts the consumer at ease and lawyers at bay. Let's now take a look at what's behind the recall.

Sony Energy Devices (Sony), the maker of the lithium-ion cells in question, says that on rare occasions microscopic metal particles may come into contact with other parts of the battery cell, leading to a short circuit within the cell. Although battery manufacturers strive to minimize the presence of metallic particles, complex assembly techniques make the elimination of all metallic dust nearly impossible.
• • Figure 1: Lithium-ion battery damages a laptop.
Safety issues are enticing battery manufacturers to change the manufacturing process. According to Sony, contamination of Cu, Al, Fe and Ni particles during the manufacturing process may cause an internal short circuit.


A mild short will only cause an elevated self-discharge. Little heat is generated because the discharging energy is very low. If, however, enough microscopic metal particles converge on one spot, a major electrical short can develop and a sizable current will flow between the positive and negative plates. This causes the temperature to rise, leading to a thermal runaway, also referred to 'venting with flame.'

Lithium-ion cells with cobalt cathodes (same as the recalled laptop batteries) should never rise above 130°C (265°F). At 150°C (302°F) the cell becomes thermally unstable, a condition that can lead to a thermal runaway in which flaming gases are vented.

During a thermal runaway, the high heat of the failing cell can propagate to the next cell, causing it to become thermally unstable as well. In some cases, a chain reaction occurs in which each cell disintegrates at its own timetable. A pack can get destroyed within a few short seconds or linger on for several hours as each cell is consumed one-by-one. To increase safety, packs are fitted with dividers to protect the failing cell from spreading to neighboring cells.

Safety level of lithium-ion systems

There are two basic types of lithium-ion chemistries: cobalt and manganese (spinel). To achieve maximum runtime, cell phones, digital cameras and laptops use cobalt-based lithium-ion. Manganese is the newer of the two chemistries and offers superior thermal stability. It can sustain temperatures of up to 250°C (482°F) before becoming unstable. In addition, manganese has a very low internal resistance and can deliver high current on demand. Increasingly, these batteries are used for power tools and medical devices. Hybrid and electric vehicles will be next.

The drawback of spinel is lower energy density. Typically, a cell made of a pure manganese cathode provides only about half the capacity of cobalt. Cell phone and laptop users would not be happy if their batteries quit halfway through the expected runtime. To find a workable compromise between high energy density, operational safety and good current delivery, manufacturers of lithium-ion batteries can mix the metals. Typical cathode materials are cobalt, nickel, manganese and iron phosphate.

Let me assure the reader that lithium-ion batteries are safe and heat related failures are rare. The battery manufacturers achieve this high reliability by adding three layers of protection. They are: [1] limiting the amount of active material to achieve a workable equilibrium of energy density and safety; [2] inclusion of various safety mechanisms within the cell; and [3] the addition of an electronic protection circuit in the battery pack.

These protection devices work in the following ways: The PTC device built into the cell acts as a protection to inhibit high current surges; the circuit interrupt device (CID) opens the electrical path if an excessively high charge voltage raises the internal cell pressure to 10 Bar (150 psi); and the safety vent allows a controlled release of gas in the event of a rapid increase in cell pressure. In addition to the mechanical safeguards, the electronic protection circuit external to the cells opens a solid-state switch if the charge voltage of any cell reaches 4.30V. A fuse cuts the current flow if the skin temperature of the cell approaches 90°C (194°F). To prevent the battery from over-discharging, the control circuit cuts off the current path at about 2.50V/cell. In some applications, the higher inherent safety of the spinel system permits the exclusion of the electric circuit. In such a case, the battery relies wholly on the protection devices that are built into the cell.

We need to keep in mind that these safety precautions are only effective if the mode of operation comes from the outside, such as with an electrical short or a faulty charger. Under normal circumstances, a lithium-ion battery will simply power down when a short circuit occurs. If, however, a defect is inherent to the electrochemical cell, such as in contamination caused by microscopic metal particles, this anomaly will go undetected. Nor can the safety circuit stop the disintegration once the cell is in thermal runaway mode. Nothing can stop it once triggered.

• The 'smart' battery (BU18)
• The battery has the inherit problem of not being able to communicate with the user. Neither weight, color, nor size provides an indication of the battery's state-of-charge (SoC) and state-of-health (SoH). The user is at the mercy of the battery.

Help is at hand in breaking the code of silence. An increasing number of today's rechargeable batteries are made 'smart'. Equipped with a microchip, these batteries are able to communicate with the charger and user alike. Typical applications for 'smart' batteries are notebook computers and video cameras. Increasingly, these batteries are also used in biomedical devices and defense applications.

There are several types of 'smart' batteries, each offering different complexities and costs. The most basic 'smart' battery may contain nothing more than a chip that sets the charger to the correct charge algorithm. In the eyes of the Smart Battery System (SBS) forum, these batteries cannot be called 'smart'.

What then makes a battery 'smart'? Definitions still vary among organizations and manufacturers. The SBS forum states that a 'smart' battery must be able to provide SoC indications. In 1990, Benchmarq was the first company to commercialize the concept by offering fuel gauge technology. Today, several manufacturers produce such chips. They range from the single wire system, to the two-wire system to the System Management Bus (SMBus). Let's first look at the single wire system.
• The Single Wire Bus
The single wire system delivers the data communications through one wire. This battery uses three wires: the common positive and negative battery terminals and one single data terminal, which also provides the clock information. For safety reasons, most battery manufacturers run a separate wire for temperature sensing. Figure 1 shows the layout of a single wire system.
• • • Figure 1: Single wire system of a 'smart' battery.Only one wire is needed for data communications. For safety reasons, most battery manufacturers run a separate wire for temperature sensing.
• The single wire system stores the battery code and tracks battery readings, including temperature, voltage, current and SoC. Because of relatively low hardware cost, the single wire system enjoys market acceptance for high-end two-way radios, camcorders and portable computing devices.

Most single wire systems do not provide a common form factor; neither do they lend themselves to standardized SoH measurements. This produces problems for a universal charger concept. The Benchmarq single wire solution, for example, cannot measure the current directly; it must be extracted from a change in capacity over time. In addition, the single wire bus allows battery SoH measurement only when the host is 'married' to a designated battery pack. Such a fixed host-battery relationship is only feasible if the original battery is used. Any discrepancy in the battery will make the system unreliable or will provide false readings.
• The SMBus

The SMBus is the most complete of all systems. It represents a large effort from the electronics industry to standardize on one communications protocol and one set of data. The Duracell/Intel SBS, which is in use today, was standardized in 1993. It is a two-wire interface system consisting of separate lines for the data and clock. Figure 2 shows the layout of the two-wire SMBus system.
• • • Figure 2: Two-wire SMBus system.The SMBus is based on a two-wire system using a standardized communications protocol. This system lends itself to standardized state-of-charge and state-of-health measurements.
• The objective behind the SMBus battery is to remove the charge control from the charger and assign it to the battery. With a true SMBus system, the battery becomes the master and the charger serves as slave that must follow the dictates of the battery.

Battery-controlled charging makes sense when considering that some packs share the same footprint but contain different chemistries, requiring alternative charge algorithms. With the SMBus, each battery receives the correct charge levels and terminates full-charge with proper detection methods. Future battery chemistries will be able to use the existing chargers.

An SMBus battery contains permanent and temporary data. The permanent data is programmed into the battery at the time of manufacturing and includes battery ID number, battery type, serial number, manufacturer's name and date of manufacture. The temporary data is acquired during use and consists of cycle count, user pattern and maintenance requirements. Some of this information is renewed during the life of the battery.

The SMBus is divided into Level 1, 2 and 3. Level 1 has been eliminated because it does not provide chemistry independent charging. Level 2 is designed for in-circuit charging. A laptop that charges its battery within the unit is a typical example of Level 2. Another Level 2 application is a battery that contains the charging circuit within the pack. Level 3 is reserved for full-featured external chargers.

External Level 3 chargers are complex and expensive. Some lower cost chargers have emerged that accommodate SMBus batteries but are not fully SBS compliant. Manufacturers of SMBus batteries do not fully endorse this shortcut. Safety is always a concern, but customers buy them because of low cost. Serious industrial battery users operating biomedical instruments, data collection devices and survey equipment use Level 3 chargers with full-fledged charge protocol.

Among the most popular SMBus batteries are the 35 and 202 form-factors (Figure 3). Manufactured by Sony, Hitachi, GP Batteries, Moli Energy and others, these batteries work (should work) in all portable equipment designed for this system. Although the 35 has a smaller footprint than the 202, most chargers accommodate both sizes. A non-SMBus ('dumb') version with same footprint is also available. These batteries can only be charged with a regular charger, or one that accepts both types.
• • • Figure 3: 35 and 202 series 'smart' batteries featuring SMBus.Available in nickel-cadmium, nickel-metal-hydride and lithium-ion chemistries, these batteries are used for laptops, biomedical instruments and survey equipment. A non-SMBus ('dumb') version with same footprint is also available.
• In spite of the agreed standard and given form factors, many computer manufacturers have retained their proprietary batteries. Safety, performance and form factor are the reasons. They argue that enduring performance can only be guaranteed if their own brand battery is used. This makes common sense but the leading motive may be pricing. In the absence of competition, these batteries can be sold for a premium price.
• Negatives of the 'smart' battery

The 'smart' battery has some notable downsides, one of which is price. An SMBus battery costs about 25% more than the 'dumb' equivalent. In addition, the 'smart' battery was intended to simplify the charger but a full-fledged Level 3 charger costs substantially more than a regular model.

A more serious drawback is the requirements for periodic calibration or capacity re-learning. The Engineering Manager of Moli Energy, a manufacturer of lithium-ion cell commented, "With lithium-ion we have eliminated the memory effect; but is the SMBus battery introducing digital memory?"

Why is calibration needed? The calibration corrects the tracking errors that occur between the battery and the digital sensing circuit while charging and discharging. The most ideal battery application, as far as fuel-gauge accuracy is concerned, would be a full charge followed by a full discharge at a constant current. In such a case, the tracking error would be less than 1% per cycle. In real life, however, a battery may be discharged for only a few minutes and the load pulses may be very short. Long storage also contributes to errors because the circuit cannot accurately compensate for self-discharge. Eventually, the true capacity of the battery no longer synchronizes with the fuel gauge and a full charge and discharge is needed to 're-learn' the battery.

How often is calibration needed? The answer lies in the battery application. For practical purposes, a calibration is recommended once every three months or after every 40 short cycles. Many batteries undergo periodic full discharges as part of regular use. If the portable device allows a deep enough discharge to reset the battery and this is done regularly, no additional calibration is needed. However, if no discharge reset has occurred for a few months, a deliberate full discharge is needed. This can be done on a charger with discharge function or a battery analyzer.

What happens if the battery is not calibrated regularly? Can such a battery be used in confidence? Most 'smart' battery chargers obey the dictates of the chemical cells rather than the electronic circuit. In this case, the battery will fully charge regardless of the fuel gauge setting and function normally, but the digital readout will become inaccurate. If not corrected, the fuel gauge simply becomes a nuisance.

An addition problem with the SMBus battery is non-compliance. Unlike other tightly regulated standards, the SMBus protocol allows some variations. This may cause problems with existing chargers and the SMBus battery should be checked for compatibility before use. The need to test and approve the marriage between a specific battery and charger is unfortunate, given the assurance that the SMBus battery is intended to be universal. Ironically, the more features offered on the SMBus charger and the battery, the higher the likelihood of incompatibilities.
• The battery fuel gauge (BU19)

When the 'smart' battery was introduced in the 1990s, one of the main objectives was to enable communications between the battery and user. Adding a fuel gauge solved this. In this paper, we evaluate various fuel gauges, check how they work, and assess their advantages and limitations. Since the System Management Bus (SMBus) is most widely used, we will focus on this system.
• The state-of-charge indicator
Most 'smart' batteries are equipped with a charge level indicator. When pressing the 'Test' button on a fully charged battery, all signal lights illuminate. On a partially discharged battery, half the lights illuminate, and on an empty battery, all lights remain dark. Figure 4 shows such a fuel gauge.
• • • Figure 4: State-of-charge readout of a 'smart' battery.Although the state-of-charge is displayed, the state-of-health and its predicted runtime are unknown.
• While SoC information displayed on a battery or computer screen is helpful, the fuel gauge resets to 100% each time the battery is recharged, regardless of the battery's SoH. A serious miscount occurs if an aged battery shows 100% after a full-charge, when in fact the charge acceptance has dropped to say 50% or less. The question remains: "100% of what?" A user unfamiliar with this battery has little information about the runtime of the pack.

The reserve capacity can only be established when the SoH is known. Figure 5 illustrates the three imaginary sections of a battery consisting of the empty zone, which can be refilled, available energy and unusable section or 'rock content' that can no longer store energy.

• • • • Empty Zone
Can be refilled • • Figure 5: Battery charge capacity.Three imaginary sections of a battery consisting of available energy, empty zone and rock content. With usage and age, the rock content grows.
• Available Energy
• Rock Content
Unsusable - can no longer store energy
• A battery fuel gauge should be able to disclose all three sections of the battery. Knowing the battery's SoH can do this. While the SoC is relatively simple to produce, measuring the SoH is more complex. Here is how it works:

At time of manufacture, each SMBus battery is given its specified SoH status, which is 100% by default. This information is permanently programmed into the pack and does not change. With each charge, the battery resets to the full-charge status. During discharge, the energy units (coulombs) are counted and compared against the 100% setting. A perfect battery would indicate 100% on a calibrated fuel gauge. As the battery ages and the charge acceptance drops, the SoH decreases. The discrepancy between the factory-set 100% and the delivered coulombs on a fully discharged battery indicates the SoH.

Knowing the SoC and SoH, a simple linear display can be made. The SoC is indicated with green LEDs; the empty part remains dark; and the unusable part is shown with red LEDs. Figure 6 shows such a tri-state fuel gauge. As an alternative, a numeric display indicating SoH and SoC can be used. The practical location for the tri-state-fuel gauge is on the charger.
• • • Figure 6: Tri-state fuel gauge. The Battery Health Gauge reads the 'learned' battery information available on the SMBus and displays it on a multi-colored LED bar. The illustration shows a partially discharged battery of 50% SoC with a 20% empty portion and an unusable portion of 30%.
• The target capacity selector

For users that simply need a go/no go answer, chargers are available that feature a target capacity selector. Adjustable to 60, 70 or 80%, the target capacity selector acts as a performance check and flags batteries that do not meet the set requirements.

If a battery falls below target, the charger triggers the condition light. The user is prompted to press the condition button to calibrate and condition the battery by applying a charge/discharge/charge cycle. The green 'ready' light at the end of the service reveals full charge and assures that the battery meets the required performance level. If the battery does not recover, a fail light indicates that the battery should be replaced. Figure 7 illustrates a two-bay Cadex charger featuring the target capacity selector and discharge circuit. This unit is based on Level 3 and services both SMBus and 'dumb' batteries.
• • • • Figure 7: The Cadex SM2+ charger This Level 3 charger serves as charger, conditioner and quality control system. It reads the battery's true state-of-health and flags those that fall below the set target capacity. Each bay operates independently and charges nickel-cadmium, nickel-metal-hydride and lithium?ion chemistries in approximately three hours. 'Dumb' batteries can also be charged but no SoH information is available.
• By allowing the user to set the desired battery performance level, the question is raised as to what level to select. The answer is governed by the application, reliability and cost.

The nominal target capacity setting is 80%. Decreasing the threshold to 70% will lower the performance standard but pass more batteries. A direct cost saving will result. The 60% level may suit those users who run a low budget operation, have ready access to replacement batteries and can live with shorter, less predictable runtimes. It should be noted that the batteries are always charged to 100%, regardless of the target setting. The target capacity simply reveals the energy, which a fully charged battery can deliver.

'Smart' batteries enabling performance readings are reserved for high-end industrial applications. However, in spite of improvements made over the last ten years, the 'smart' battery, the SMBus in particular, has not received the anticipated acceptance. Some engineers go so far as to suggest that the SMBus battery is a 'misguided principal'.

Part of the problem is the periodic calibration that is needed to correct the tracking errors that occur between the battery and the digital sensing circuit. Notable errors transpire if a battery is charged and discharged for only brief moments and the load varies widely. Long storage also contributes to errors because the circuit cannot accurately compensate for self-discharge.

Regardless of these limitations, the 'smart' battery will continue to serve a critical market. It is conceivable that other methods will be introduced that do not rely on the in and out-flow of energy to establish energy reserve. But the importance of the fuel gauge has been established. There are simply no alternatives for users to whom unexpected downtime is no option.
• How to store batteries (BU20)

Batteries are perishable products that start deteriorating right from the moment they leave the factory. There are simple preventive measures that battery users can apply to slow the aging process. This paper provides guidelines to reduce age-related capacity losses and how to prime new and stored batteries.

The recommended storage temperature for most batteries is 15°C (59°F). While lead-acid batteries must always be kept at full charge, nickel and lithium-based chemistries should be stored at 40% state-of-charge (SoC). This level minimizes age-related capacity loss, yet keeps the battery in operating condition even with some self-discharge. While the open terminal voltage of nickel-based batteries cannot be used to determine the SoC accurately, voltage fuel gauging works well for lithium-ion cells. However, differences in the electrochemistry of the electrodes and electrolyte between manufacturers vary the voltage profile slightly. A SoC of 50% reads about 3.8V; 40% is 3.75V. Store lithium-ion at an open terminal voltage of 3.75-3.80V. Allow the battery to rest 90 minutes after charge before taking the voltage reading.


• Laptop Battery Life - Myths And Realities
• Laptop battery life is a topic that results in more support calls than any other topic, manufacturer’s world wide jump would for joy if they could put to rest the myth and expectations around the laptop battery life of their machines. But it is my opinion that this resolve needs to begin with the manufacturers themselves.

When these guys produce a new spec laptop they will always be competing with their opposition, so having a laptop that performs well on paper will help them sell against another competitor’s machine.

It's just human nature to want more bang for your buck, we are a greedy animal that craves more!!! So when we go on our search to find the mystical laptop that blitzes all the rest we look at product specs in the media, papers and our beloved internet. What we find are the manufacturers tested specifications that we all assume are black and white.

Not so.. some of the specs listed are not black and white. There is generally fine print for a lot of the specs you see advertised. Here are some examples.

An advertised 40GB HDD is indeed a badged, stamped and stickered 40GB but you will only get 37 or 38GB that you can use.
Optical drives are also subject to limitations, how often do you see a laptop advertised with a Super Multi drive which makes you excited at the thought of it being SUPER, you then get your SUPER drive only to find it ain’t so SUPER.

You then see the fine print under the basic specs like this "CD-ROM (24x), CD-R (24x), CD-RW (4x), DVD-ROM (8x), DVD-R (8x), DVD-RW (4x),DVD+R (8x), DVD+RW (4x), DVD-RAM (3x)". Its not super at all, its normal.

You will almost never get the extended laptop battery life advertised from the spec sheet, you may come close if you set the machine up and use it as it was used during spec testing which may be 4 - 6.5hrs battery life if the machine is left idle with all power configurations and settings set to low.

Well laptop batteries are the same, your laptop battery life is subject to use, conditions and configurations. Battery life is advertised in hours of use.. what sort of use?? If I watch a several DVD’s in a row will I still get the advertised 4 or 6 hours extended battery life?
The answer is most likely no, in fact to get 1 movie in before your laptop starts beeping at you to plug it in is good. This may lead you to believe that there is a problem with the battery or the machine, you call the helpdesk and they then inform you of the limitations.

It's important to note that a laptops battery life is directly affected by what function you perform. As you use different devices in the machine the power consumption changes, some devices use more or less power than others. As a conclusion to all this your laptop battery will last as long as it can subject to what you are doing with your machine.


• Laptop MotherBoard Repair And Diagnosis
• All we can say about laptop motherboard repair is that unless you have some of the latest diagnostic equipment, a test jig, ESD setup workshop, an array of tools, digital multi meters and an oscilloscope then don’t think you can narrow down your fault diagnosis to the exact component that is causing your laptop to misbehave... nobody has that much time.

What I can also say is that even your local authorized repair centres for all the brand name laptops don’t go to this much trouble either. I have personally been present for a number of different manufacturers’ service calls and witnessed how they operate.

For example -

If you log a call for your Acer laptop which is in warranty, the technician will turn up (for onsite warranty) with a fist full of spare parts. He will take a quick look at the machine, keeping in mind they already have a fault description and have narrowed it down prior to turning up. After looking at the machine and verifying it has a fault they will basically gut the machine and rebuild it with new internal parts.

I have seen this same technique carried out by IBM, HP/Compaq, Acer and I assume most others would do the same. This excludes Toshiba who have a different system.

Here are some things you can do to isolate what sort of problem you have, you may think you'll have to undertake some sort of laptop motherboard repair but quite often the motherboard gets blamed for a fault that may be somewhere else in your machine.

Look closely at the symptoms, determine when the fault occurs (unless it’s constant) and try and pinpoint the function that is failing.

Here is a good example.

Your screen goes dim and appears to switch off whilst in use.

- Try the machine using an external screen.

You can already get some idea here of what may be the problem, if the external screen is working it may be the LCD or the inverter board.

If the external video doesn’t work either then you mustn’t assume the LCD is faulty as you would have external display if it was just the LCD panel.

You could now suspect the video card or chipset, in which case you would need to find out whether the video chipset is part of the motherboard or on a separate PCB.

This is where your authorized repair centre will come in handy, give them your machine type and they should be able to tell you, if they can't burn their number and never call them again, they're a waste of time, find another repair centre.

I wouldn’t expect that most people would be game enough to pull their own laptop apart just to stare blankly at the exposed motherboard looking for the faulty component or track to jump out at them, it's not going to glow red or have smoke coming out of it so the whole venture would be fruitless.

Another example.

External port faults are common, like USB ports and headphone jacks. An easy way of determining these sorts of faults is to plug in as many different devices that suit to see if it is indeed the port or the device which is faulty. Also try uninstalling then reinstalling the USB device. If the function doesn’t return after this sort of work then you can go one step further and reinstall Windows (or Linux) using your recovery cd’s or your own created SOE , remember to BACKUP your data first.

If the fault is still present after this then you can assume that your hardware is to blame for the issues. Finding out what part the actual hardware (USB ports) are located on should be your next step. These sorts of ports are not always located on the main board and will often be found on a smaller less expensive board.

Do your testing using normal basic methods to determine as closely as you can what part may be causing your problem then seek some advice from a professional to see if their opinion is the same.

Sometimes it may be a case of having to replace components and use a process of elimination to find what's at fault, obviously if your optical drive seems to be playing up and you're able to plug in another one that you know is good and the problem remains your next step is to look at some sort of laptop motherboard repair, unless you're a whiz bang electronics tech this will probably mean just replacing the board.

• Do-It-Yourself laptop and notebook repair tips and tricks
• Inside my laptop
• HP Pavilion dv9000 laptop. Removing hard drive, memory, wireless card, keyboard.



• These instructions will help you remove hard drive, memory, wireless card and keyboard from a HP Pavilion dv9000 series laptop. All these components, except the keyboard, can be accessed through the bottom of the laptop.
• In the next guide I will explain how to disassemble laptop display panel and remove inverter board with LCD screen.
• Do not disassemble your laptop if it’s still covered by the manufacturer’s warranty or you loose the warranty. Are you looking for spare parts for your HP Pavilion dv9000 laptop? Search here.

• First of all, remove the battery. Remove screws from the 1st hard drive and memory covers. Remove both covers.

• Under the memory cover you will find the wireless card and RTC battery.

• In order to remove the hard drive, lift up the right side of the drive assembly (move 1) and then pull it to the right (move2). If you are replacing the hard drive, you’ll have to transfer the caddy and connector to the new drive.

• Before you remove the wireless card, you’ll have to disconnect both antenna cables pointed with green arrows. Simply unsnap both antenna cables from the wireless card with your fingers. After that remove two screws securing the wireless card and pull it from the slot by the edges.

• Some Pavilion dv9000 laptops have only one hard drive installed. As you see, in my case there is no second hard drive under the cover.

• If you would like to install second hard drive into your notebook, you’ll have to purchase a new SATA drive, SATA connector and drive caddy. You’ll find step by step hard drive installation instructions in this guide.
• we will refer to all HP Pavilion dv9000, dv9000t, dv9100, dv9200, dv9300, dv9400, dv9500, dv9600 & dv9700 notebooks as the “dv9000″ since adding a hard disk drive (HDD) to all above mentioned notebooks are similar.

• In order to remove the CD/DVD drive you’ll have to remove the securing screw (1) and then carefully pull the drive from the laptop.
• KEYBOARD REMOVAL INSTRUCTIONS

• Remove six green screws securing the keyboard bezel and one red screw securing the keyboard.

• Carefully start removing the keyboard bezel with a small flathead screwdriver.

• Be very carefull, the bezel is attached to the motherboard with a flat ribbon cable. The cable location is pointed by the green arrow. Do not disconnect this cable. Simply place the bezel as it shown on the picture below.

• Remove three screws securing the laptop keyboard.

• Lift up the keyboard. Be carefull, it’s connected to the motherboard.

• In order to release the keyboard cable, you’ll have to unlock the connector as it shown on the picture above.
1. Slide the connector lock to the direction shown by two green arrows with your fingernails.
2. Pull the keyboard cable from the connector.

• Now you can remove and replace the keyboard with a new one. You’ll find more detailed laptop disassembly instructions in the official service manual for HP Pavilion dv9000 (3.72MB pdf file).





• Tips On How To Test Your Notebook
• On this page we've covered a few techniques to test your notebook for properly functioning components.

Optical Drive Issues: (DVD/CDRW or CD/DVD or DVDRW)

Not a lot of testing required here, most of the time they work or they don’t. In the case of cd burning issues, ensure you try different media if you are having problems with disc’s failing mid burn, reinstalling or using different burning software is a must as well.

If you have a removable drive always try and reseat the drive (eject and plug back in) this can often work, the drive may have moved in transit.

FDD drives:

Issues with floppy drives are often terminal and will 90% of the time result in replacing the entire drive, more often faults with these drives are mechanical ones which causes the drive to no longer read discs.

Network and Modem:

To test your notebook for internal network and modem issues is quite simple. For modems just ensure everything is connected properly and you have an available phone line. Use Windows own HyperTerminal (Start/Programs/Accessories/Communications) to create a test dialup to your cell phone or additional phone line. If this still fails, uninstall and then reinstall the modem from Device Manager.

Most of the notebook modems are a separate little module that in most cases is easily replaced if after all this testing you still have no luck.

Network cards are generally a part of modern day motherboards so if yours is faulty you may want to look at a PCMCIA network card as a cheaper option.

Sound issues:

If have a problem with your laptop's sound system there are a couple of ways to test your notebook to determine if it is indeed the sound chipset which is faulty.

If you have no sound through the speaker or headphone jack try reinstalling the sound device and checking all your sound properties, check to ensure the sound hasn’t been muted accidentally with a function key on the keyboard.

If you have sound via the headphone jack and not the speakers then the sound chipset is OK and you have an issue either with the speakers themselves or the headphone jack may be faulty and not switching back to the speakers when the headphone plug is removed.

You may find that after following these procedures to test your notebook that the component or drive seems OK, and then it's time to look at your motherboard for faults.


• How To Take Your Laptop Apart
• Laptop Disassembly Procedure.

This is a guide on how to take your laptop apart, it's based on one particular model and won't tell you how to take your laptop apart exactly, it's meant to be used as a general guide on how to disassemble a laptop and should be used to get an understanding of how they're put together.

This page has step by step instructions with quite a few images, it may take a few seconds to load so please be patient.

OK, remember not to undertake this sort of thing unless you are confident you can see it through. Please begin by reading the safety instructions below.

Before You Begin.
Look over the procedures in this section before you begin to take the laptop apart. Familiarize yourself with the disassembly and reassembly steps. Begin each procedure by removing the AC adaptor and the battery pack.

Points to note.
1. Do not take your laptop apart unless it is operating abnormally.

2. Use only the correct and approved tools.

3. Make sure the working environment is free from the following elements whether you are using or storing the laptop.

- Dust and contaminates
- Static electricity
- Extreme heat, cold and humidity

4. Make sure the FRU you are replacing is causing the abnormal operation by performing the necessary troubleshooting and diagnostics tests.

5. As you take your laptop apart, place any removed components in a safe place away from the computer so they will not be damaged and will not interfere with your work.

6. You will remove and replace many screws as you disassemble your laptop. When you remove screws, make sure they are placed in a safe place and identified with the correct parts.

7. When assembling the computer make sure you use the correct screws to secure the various pieces. Screw sizes are listed in their corresponding figures.

8. After you have replaced an FRU, make sure the computer is functioning properly by performing the appropriate test on the FRU you have fixed or replaced.

This guide explains how to take your laptop apart and replace Field Replaceable Units (FRUs). It may not be necessary to remove all the FRUs in order to replace one. The chart below is a guide to which FRUs need to be removed in order to remove others. Always start by removing the battery pack, next remove optional items such as the PC Card, then follow the chart downward removing only those FRUs necessary to reach the one you think is causing the computer to operate improperly.

Refer to the diagram below.



The diagram below shows FRUs to be removed before the Direct Play button board can be removed and repaired or replaced. The Direct Play button board is overlapped by the top cover which must be removed before the Direct Play button board can be reached.

The removable HDD, keyboard, wireless LAN, ODD, modem, and display assembly in turn overlap the top cover. Before you begin to take your laptop apart always start the disassembly process by removing the battery pack.



Removing the Battery Pack
To remove the battery pack from the battery bay, follow the steps below.
1. Turn the computer upside down.
2. Unlock the battery double lock and slide the battery bay latch to release the battery pack. Then you can remove it from the bay.

• Removing the HDD Module
Follow the steps below to remove HDD module:
1. Turn the computer upside down
2. Remove two black M2.5x5 screws to release the HDD door.
3. Pull out the tab to remove the HDD unit.

• Removing the Optical Drive Module
To remove the optical drive module, you need to remove the HDD unit first. Follow the steps below:
1. Turn the computer upside down.
2. Follow the steps above to remove the HDD unit.
3. Remove one M2.5x8 screw and slide the optical drive module from the bay.


A lot of laptops have a select bay or removable drives not requiring any screw removal, in those cases simply eject the drive.

Removing the Wireless LAN Unit
1. Turn the computer upside down and loosen the screw securing the wireless LAN compartment cover.
2. Lift off the wireless LAN compartment cover.
3. Remove the embedded screw M2.5x5 securing Mini PCI bracket.
4. Detach the two ends of the wireless LAN antenna.


You may need a Hex or Torq (T7) screwdriver to access the Wifi card.

5. Gently press out on the latches. One end of the wireless LAN unit will pop up.
6. Grasp the wireless LAN unit and pull it out.



Removing the Expansion Memory
To remove the memory module, make sure the computer is in boot mode then:
1. Be sure the power is off and all cables are disconnected from the computer.
2. Turn the computer upside down and remove the battery and the screw securing the memory module socket cover.
3. Slide your fingernail or a thin object under the cover and lift it off.
4. Push the latches to the outside to release the module. A spring will force one end of the module up.
5. Grasp the module and pull it out.
6. Seat the cover and secure its screws.
7. Replace the battery.



Remove the memory bay cover (see below).




Removing the Keyboard
• Removing the Modem
To remove the installed modem, first remove the strip cover and keyboard, then follow the steps below:
1. Remove two black M2.5x3 screws securing the modem module.
2. Carefully lift the unit off its connector.
3. Disconnect the modem cable from the modem module.


Modem removal in a system with the modem mounted under the keyboard, a lot of laptops have an access panel from the underside.

Removing the Display Assembly
Removing the Cover
To remove the top cover, first remove the battery pack, display assembly, optical drive module, HDD, memory module and wireless LAN, then follow the steps below:

1. Remove five black M2.5x8 black screws and one black M2.5x3 screw securing the top cover.
2. Detach the upper FFC cable and two speaker cables on the top chassis.
3. Remove the two black M2.5x8 screws securing the system board.
4. Turn the computer upside down and remove the following sixteen screws as shown in the diagram below
5. Turn the computer upright to lift off the top cover.


Top cover assembly.



Removing the System Board
To remove your laptop's mainboard, first remove the LCD assembly and top cover, then follow the steps below:
1. Remove the two black M2.5x8 screws securing the system board to the bottom cover.
2. Remove the two or four silver screws securing the system board to the backside.
3. Remove the system board from the chassis.



Mainboard screws will vary from 1 or 2 up to 10 or more. Remember to disconnect any cables that are connected.



These instructions should be only used as a guide to give you an understanding on how to take your laptop apart. If you're not 100% sure of what you're doing if may be a better idea to pay a technician to take your laptop apart and repair it.




• Tips On How To Test Your Notebook
• On this page we've covered a few techniques to test your notebook for properly functioning components.

Optical Drive Issues: (DVD/CDRW or CD/DVD or DVDRW)

Not a lot of testing required here, most of the time they work or they don’t. In the case of cd burning issues, ensure you try different media if you are having problems with disc’s failing mid burn, reinstalling or using different burning software is a must as well.

If you have a removable drive always try and reseat the drive (eject and plug back in) this can often work, the drive may have moved in transit.

FDD drives:

Issues with floppy drives are often terminal and will 90% of the time result in replacing the entire drive, more often faults with these drives are mechanical ones which causes the drive to no longer read discs.

Network and Modem:

To test your notebook for internal network and modem issues is quite simple. For modems just ensure everything is connected properly and you have an available phone line. Use Windows own HyperTerminal (Start/Programs/Accessories/Communications) to create a test dialup to your cell phone or additional phone line. If this still fails, uninstall and then reinstall the modem from Device Manager.

Most of the notebook modems are a separate little module that in most cases is easily replaced if after all this testing you still have no luck.

Network cards are generally a part of modern day motherboards so if yours is faulty you may want to look at a PCMCIA network card as a cheaper option.

Sound issues:

If have a problem with your laptop's sound system there are a couple of ways to test your notebook to determine if it is indeed the sound chipset which is faulty.

If you have no sound through the speaker or headphone jack try reinstalling the sound device and checking all your sound properties, check to ensure the sound hasn’t been muted accidentally with a function key on the keyboard.

If you have sound via the headphone jack and not the speakers then the sound chipset is OK and you have an issue either with the speakers themselves or the headphone jack may be faulty and not switching back to the speakers when the headphone plug is removed.

You may find that after following these procedures to test your notebook that the component or drive seems OK, and then it's time to look at your motherboard for faults.

• Laptop MotherBoard Repair And Diagnosis
• All we can say about laptop motherboard repair is that unless you have some of the latest diagnostic equipment, a test jig, ESD setup workshop, an array of tools, digital multi meters and an oscilloscope then don’t think you can narrow down your fault diagnosis to the exact component that is causing your laptop to misbehave... nobody has that much time.

What I can also say is that even your local authorized repair centre for all the brand name laptops doesn’t go to this much trouble either. I have personally been present for a number of different manufacturers’ service calls and witnessed how they operate.

For example -

If you log a call for your Acer laptop which is in warranty, the technician will turn up (for onsite warranty) with a fist full of spare parts. He will take a quick look at the machine, keeping in mind they already have a fault description and have narrowed it down prior to turning up. After looking at the machine and verifying it has a fault they will basically gut the machine and rebuild it with new internal parts.

I have seen this same technique carried out by IBM, HP/Compaq, Acer and I assume most others would do the same. This excludes Toshiba who have a different system.

Here are some things you can do to isolate what sort of problem you have, you may think you'll have to undertake some sort of laptop motherboard repair but quite often the motherboard gets blamed for a fault that may be somewhere else in your machine.

Look closely at the symptoms, determine when the fault occurs (unless it’s constant) and try and pinpoint the function that is failing.

Here is a good example.

Your screen goes dim and appears to switch off whilst in use.

- Try the machine using an external screen.

You can already get some idea here of what may be the problem, if the external screen is working it may be the LCD or the inverter board.

If the external video doesn’t work either then you mustn’t assume the LCD is faulty as you would have external display if it was just the LCD panel.

You could now suspect the video card or chipset, in which case you would need to find out whether the video chipset is part of the motherboard or on a separate PCB.

This is where your authorized repair centre will come in handy, give them your machine type and they should be able to tell you, if they can't burn their number and never call them again, they're a waste of time, find another repair centre.

I wouldn’t expect that most people would be game enough to pull their own laptop apart just to stare blankly at the exposed motherboard looking for the faulty component or track to jump out at them, it's not going to glow red or have smoke coming out of it so the whole venture would be fruitless.

Another example.

External port faults are common, like USB ports and headphone jacks. An easy way of determining these sorts of faults is to plug in as many different devices that suit to see if it is indeed the port or the device which is faulty. Also try uninstalling then reinstalling the USB device. If the function doesn’t return after this sort of work then you can go one step further and reinstall Windows (or Linux) using your recovery cd’s or your own created SOE , remember to BACKUP your data first.

If the fault is still present after this then you can assume that your hardware is to blame for the issues. Finding out what part the actual hardware (USB ports) are located on should be your next step. These sort of ports are not always located on the main board and will often be found on a smaller less expensive board.

Do your testing using normal basic methods to determine as closely as you can what part may be causing your problem then seek some advice from a professional to see if their opinion is the same.

Sometimes it may be a case of having to replace components and use a process of elimination to find what's at fault, obviously if your optical drive seems to be playing up and you're able to plug in another one that you know is good and the problem remains your next step is to look at some sort of laptop motherboard repair, unless you're a whiz bang electronics tech this will probably mean just replacing the board.






• 'How To Laptop Repair' Photo Guides
• What we're trying to do with this series of 'How to laptop repair' guides is to give a general photo assisted procedure for some specific laptop repairs.

Obviously we can’t encompass all makes and models in this section so what we have done is to put together some info based on Toshiba laptop repair but is also good general info for the following tasks..


Repairs like these are not difficult to do as long as you have a little patience and a general understanding of our instructions.

An exclusion from these topics is main board replacement; this is something we feel has too much variation from machine to machine.

You will need some tools like a Phillips head screwdriver and a flat blade screwdriver, it's not a bad idea to try and use some ESD (Electrostatic Discharge) protection too. If you can, great, if not you’ll have to take the risk. You can minimize this by choosing a suitable work area, i.e. no carpet or rugs.












• Laptop LCD Repair - A Photo Guide
• If you're undertaking some laptop LCD repair, removing and replacing your screen means you are working with a very fragile and very expensive component.

Follow these steps carefully, the machine in the photos here is a Toshiba but the job is quite similar regardless of what brand machine you are working on.







Remove the mask stickers and then the screws from behind the stickers.



Carefully pull away the mask assembly from around the screen.
• Remove the LCD mounting screws behind the stickers and also behind the inverter cable.



The LCD should now be free from its mountings.



Disconnect the cable from the back of the LCD.

To complete your laptop LCD repair and fit your new screen, just reverse the steps above.











• Laptop Repair Manuals
• Having a laptop repair manual specific to your machine is invaluable when you're performing maintenance or repairs.
Maintenance and service guides provide a range of information including -
• Models numbers for your machine specific to the country you're in (essential to know when ordering spare parts).
• Troubleshooting guides.
• Component lists and layouts.
• Machine specific disassembly and service guides.
• Cable and connector wiring configurations and assignments.



Note: There is quite a bit of interchangeability between Compaq and HP machines so if you can't find the service manual for your machine in the Compaq section please check the HP section.










• How To Clear Your Bios Password
• You might find you need to clear your bios password on your laptop if you have had the motherboard replaced or perhaps you've simply forgotten what your password is. A bios password is also often used as a hardware level security precaution, this is all good and well but if you need to bypass your password then the procedure can be difficult.

We've put together some guides explaining how to either bypass or clear your bios password on a range of different machines.
Please note that these procedures may make your machine inoperable or could cause permanent system damage, so proceed entirely at your own risk (please take notice of this).
• Acer Bios Password Removal
• If you need to remove your Acer bios password from your Travelmate 3290, then follow this guide.

Please note: This bypass procedure is similar for most Travelmate machines but it would be a good idea to consult a repair manual to check the exact details for your model first. Also, there are some basic precautions you should take when working on your laptop, have a quick look at some points to note in our general laptop repair guide.



1. Disconnect the power supply and the battery.

2. Unplug and remove the keyboard.



3. In between the video chip and the keyboard connector you will see a set of 4 dip switches (circled in yellow in the picture above).

4. Move switch 1 ,up.

5. Re-start the laptop and press Ctrl+F2 simultaneously as it boots, this will get you into the BIOS.

6. Set the BIOS password to disable and press Enter.

7. The machine will ask you if you want to Exit and Save the Changes, click Yes.

8. It will then boot into Windows. Re-start the computer and if there is no password then you can proceed to step 9. If there is still a BIOS password then you must repeat steps 1-8 until the password is removed.

9. Back at the main board; push the switch at the number 1 slot down, back to its original position.

10. Re-start the laptop.

11. The Acer BIOS password should now have been removed and the machine should now boot straight into Windows.








• Laptop Repair Parts Links And Resources
• Just a little bit of info when sourcing laptop repair parts -

Be careful when attempting to do any sort of part replacement in your laptop that involves purchasing any model specific parts, i.e. any PCB replacement big or small. Because of subtle differences between models sold in different parts of the world not all internal parts are the same even if your model name or number is.

It's best to consult a technician who is familiar with the brand of notebook you have, do this by starting with the manufacturer's recommended or authorized repairers.

Below is a list of links for parts for some of the major notebook and laptop computer manufacturers. Use these links to track down repair parts and to compare prices between suppliers.

• HP And Compaq Laptop Repair Parts
• Finding Compaq laptop repair parts and HP laptop parts can be difficult so we have done some of the searching for you. Use the links at the bottom of the page to compare prices for the parts you need.

Please also check if the supplier you choose can ship the part to your location before you order.

Check the returns policy and warranty terms for the supplier before you order, this will make things easier if you order the wrong part.

We've outlined the main points to be mindful of below.

- Find out if the parts supplier charges a fee if you return a part. They may call it a 'restocking' fee and can charge a percentage or a flat fee.

- Is there a time limit on returning a part?

- Who picks up the freight and shipping charges for a return or exchange?

- The vendor will usually say they're not responsible for any damage or defects caused by improper handling, storage or unauthorized repair. This is fair enough, after all they can't control what you do with a part once you receive it but if you're doing your own repair at home then you aren't an authorized repairer and you'll be responsible if you damage a part by doing the wrong thing.

If you ensure you can work within these requirements then you should be ok.

• How To Repair Your Laptop Power Plug / Jack
• It's almost inevitable that you'll need to repair your laptop power plug if you own a Toshiba Satellite A70 unless you've already had the main board replaced in which Toshiba have applied a well overdue modification similar to what you’ll see here.

The DC jacks on these units are weakened over time with general use and become unstable and loose, in some cases detaching themselves from the main board altogether.

In the one we have pictured the plug detached from the board completely and had to be resoldered and modified due to the rear pin connection breaking away from the plug. You can see the red wire which had to be added to replace the broken pin; this won't always have to be done.

Once the plug has had all of its board mounted points resoldered it is advisable to add an epoxy resin around the outer edge of the plug to fix it to the main board, this will minimize movement when the adapter is plugged into it. I generally use Araldite.



• Toshiba Satellite A70 with damaged AC plug. PCB view from the top after modification.

The above photo shows the points that need to be resoldered, the 3 points in a row above the red wire (which is our mod) and normally where the red wire is as well.







The red arrows in the above pictures indicate where resin has been added all around the base of the AC plug.

If you need to repair your laptop power plug, this fix will work well in just about any make of machine.

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