How to disassemble keyboard

In this guide I show how to disassemble a laptop keyboard.
I’m doing it for fun just to see how it’s built. I’m taking apart a damaged one and have no intention to use it in the future.


I’ll be using one of my tools shown on the following picture.

STEP 1.
Remove sticky tape securing the cable to back of the keyboard.

STEP 2.
Carefully unglue the cable from the back.

STEP 3.
Start peeling off the aluminum protective film.

STEP 4.
Remove the protective film.
After the protective film is removed it cannot be reused.

STEP 5.
My keyboard had two plastic separators on the top.

They are secured to the back via pins.
Plastic pins are melted on the back and secure separators in place.

Push all plastic pins though wholes on the keyboard.

Start removing the separator.

The separator has been removed.

STEP 6.
Now you’ll have to remove all key caps.

In order to remove the key cap carefully lift it up with your fingers.

Remove the key cap so the hinge underneath stays connected to the keyboard.

Some big keys have a different design.
In addition to the hinge, some big keys (Back space or Space bar for example) might have an additional support bracket.

Remove the key cap with the support bracket.

STEP 7.
Some laptop keyboards might have blank covers on the left and right sides from the up arrow key.

Lift up and remove the blank cover.

All key caps and plastic separators have been removed.

STEP 8.
Now you can start removing key hinges – key lifting mechanisms.

Carefully separate the key hinge from the keyboard body.

Each key hinge has two parts – external and internal pieces.
When you remove the hinge, try to keep the internal part inside the external. Do not separate them.

If they separated, put them back together.

The lifting mechanism (hinge) assembled.

As I mentioned at the beginning, I’m taking this keyboard apart just for fun. That’s why I don’t care about removed parts.
If you following this guide to repair the keyboard, I would recommend to keep all hinges in the right order.

STEP 9.
Remove the sheet with silicone (or rubber) plungers.

STEP 10.
Remove the second sheet with traces.

Both sheets have been separated from the base.

STEP 11.
The sheet with traces has two layers and all traces are running between these layers.

STEP 12.
You can separate these layers from each other.

The keyboard has been disassemble.

Can you repair a keyboard? My answer is NO! Keyboards are cheap and not designed to be disassembled.
Also read how to repair individual keys.

How to fix broken keyboard connector

In this guide I explains how to fix a broken keyboard connector on a laptop motherboard.

The connector is a very delicate mechanism. It’s very easy to get it damaged if you apply too much force while trying to unlock it.
The cable retainer (locking clip) is made of thin plastic and if it’s damaged, you are in trouble. Unfortunately, this part is not sold separately.
Well… let’s say it happened. The damage is done. How to fix it now?

On the picture below I show one of the most common connector types. It has the base (white in my case) and cable retainer (brown in my case).
When the connector is closed, the cable secured between the retainer and base.
The retainer applies some pressure on the cable and it makes contact with the pins inside the connector.
To unlock it properly, you have to move the retainer about 2 millimeters in the direction shown by two yellow arrows.
IMPORTANT! The retainer must remain attached base.
After that you can pull the keyboard cable and remove the keyboard.

If you are not careful enough, you can move the retainer too far and break it.
On the picture below you can see the retainer broken on both sides. It is missing the both locking hook.

IMPORTANT! Do not though away the retainer. You still can use it.

The cable will not stay inside the connector without the locking clip.

Here’s how fix this type of damage.
Position the broken piece the way it was inserted before.

Carefully insert the cable into the connector. In this case the cable goes above the retainer.

While holding the cable, carefully push the broken clip back in place. You can use a small screwdriver for that.
The clip fits tightly into the connector even though it has two broken hooks.

Secure the connection with sticky tape and test the keyboard. It should work just fine.

Here’s another connector type. The only difference – the keyboard cable is routed under the locking clip. Fix it the same way as the previous connector.

On the next picture you see another type of connector. The cable is inserted vertically.

In order to unlock the connector, you’ll have to move the locking clip (brown piece) about 2 millimeters up in the direction shown by two yellow arrows.
After that you can pull the keyboard cable (green arrow) and remove the keyboard.

If you move the locking clip too far, you can break it.
In my example one side of the retainer got damaged.

Insert the keyboard cable into the connector, position the broken retainer correctly (behind the cable in my case) and carefully push it in.
Even with a broken retainer the cable should be secured inside the connector.

Here’s the same connector shown from the opposite side. You cannot even tell it is broken.

If this trick worked for you, it means I just saved you big bucks on the motherboard replacement. And I’m glad I did.
REPAIR TIPS FROM READERS:
Thank you to Alex for the following suggestion:
I found another way to fix it…
Have you lost the broken “Locking clip”?
Then do this…
Get some “electrical tape” on the back of the “flat cable” to make some “thickness”.
Make sure you are putting the tape on the right side, where there are no visible connections…
Then very carefully push the cable into the connector… It will not come loose and the keyboard will work just fine!
Also read this post explaining how to repair broken touchpad connector.

How to fix hardware problems

In this guide I show how to work around some common laptop hardware problems without taking it apart.
1. Network port failure.
Most motherboards have the network port permanently attached. If the network port fails (I’m talking about hardware, not software failure), the whole motherboard has to be replaced.
Instead of replacing the motherboard, you can use a PCMCIA network card. You plug this card into the available PC slot in your laptop and you are back in business.

If you computer doesn’t have a PC slot, you can use a USB Ethernet adapter instead.

2. USB ports failure.
Most laptops have a few USB ports available. If one of them stops working, usually it’s not a big deal because you still have two or three more working ports left.
But what if all of them stopped working at once? Let’s say the USB controller on the motherboard went bad and the laptop stopped recognizing any device plugged into any USB port. Again, I’m talking about hardware, not software failure. In order to fix this problem you’ll have to replace the motherboard.
Alternatively, you can use a PCMCIA USB card. You plug this card into the PC slot and get two or four USB ports instead. It depends on the type of your PCMCIA card.

3. Internal wireless (Wi-Fi) card failure.
What can you do if the internal wireless card failed?
You can replace the failed wireless card with another one or use a PCMCIA wireless card instead.

4. Internal flash memory card reader failure.
Most newer laptops come with a flash memory card reader. Usually the card reader is soldered directly to the motherboard and if it fails, you have to replace the whole motherboard.
Alternatively, you can use an external USB flash memory card reader. All you have to do is plug the card reader into the available USB port and it’s ready to go.

5. Internal CD/DVD drive failure.
You’ll find an internal CD/DVD optical drive in most computers. If the optical drive failed and stopped reading discs, it has to be replaced with a new one.
Instead of replacing the failed drive, you can use an external USB drive. Simply plug this drive into the USB port, let your computer detect the drive and it’s ready for you.
Also, you can use this optical drive with any other computer which is very convenient.

How to test screen inverter

In this post I explain how I test the inverter board in a laptop.
The inverter failure is very similar to the backlight lamp failure. In both cases the screen gets very dark and the image becomes very faint, barely visible under a bright light.

There is only one reliable way to test the inverter – replacing it with another one and see if the screen lights up after that.
Alternatively, you can connect a new backlight lamp and see if your presumably bad inverter lights it up.

In most cases I go with the second method – using my test backlight lamp. Why? Because the same backlight lamp will work with many different inverters as long as they have matching connectors.
Usually the inverter is mounted inside the display panel below the screen. In most cases you can access it after you remove the display bezel. The inverter has connectors on both ends. The left side connects to the LCD cable. The right side connects to the backlight lamp which is mounted inside the screen. Check out this display diagram.
To make sure that inverter gets power from the motherboard (via the LCD cable), you can test it with a voltmeter. In my case I connected the “+” lead of the voltmeter to the pin 1 and the “-” lead to the ground trace around the screw hole. I got about 19.4V DC on that side of the board, so it’s getting power from the motherboard.
WARNING! If you accidentally short something on the inverter while testing, you can damage it. Proceed on your own risk! Not sure? Don’t do that!

So far we know the inverter is getting power from the motherboard, but the screen still has no light. Apparently, it’s either bad inverter or failed backlight lamp.
Now let’s test it with a known good backlight lamp.
1. Unplug the screen backlight cable from the right side of the inverter.
2. Connect a known good backlight lamp.
Turn on the laptop.
1. If the test backlight turns on, the lamp inside the screen is bad. In this case you’ll have to replace the screen. Also, you can replace the backligth lamp which is not easy and not recommended.
2. If the test backlight doesn’t turn on, most likely we have inverter failure. Replace it and test the laptop again.

There are two different types of backlight connector, you can see them on the picture below. The top one (big) is not as common as the bottom one (small). I mostly use lamps with a small connector.
IMPORTANT! When you buy a new lamp for test, make sure the connector fits your inverter.

On the following picture you see how I’m testing the laptop with a new lamp.

Related articles:
Troubleshooting backlight failure.
Screen shows strange colors.
Troubleshooting video problems.

How to modify damaged DC jack

In this guide I explain how to modify damaged DC jack. While replacing the DC jack a few days ago I accidentally damaged one of the thermals on the motherboard.
I pulled out the internal copper coating (I name it a sleeve) from the inside of the “+” terminal as it shown on the picture below.


The the sleeve removed, it cannot be installed back. If you solder the DC jack back in place without this sleeve, it might work but the connection between the “+” lead and motherboard will not be reliable.
The following guide will help you to modify damaged DC jack terminal. This modification should work for most motherboards with soldered power jack.

Remove the copper sleeve from the “+” terminal on the jack.

Find a small resistor or capacitor with thin leads. Cut off one of the leads. I’m going to use it to modify the motherboard terminal.
Shape the lead as it shown on the picture below.

Put the lead on the “+” connector on the power jack.

Solder the lead to the power jack.

Now I’m going to modify the “+” terminal on the motherboard.

Carefully scrape off green varnish around the whole on the “+” terminal on the motherboard. You can use a small flathead screwdriver.

If the whole is not big enough for your modified DC jack, you can widen it with an awl.

As you see, the hole on the terminal is now larger. Apply a fresh coat of solder on the clear area of the trace.

Install the power jack on the motherboard. Make sure there is no gap between the jack and motherboard.

Here’s a view from the top side of the PCB.
Solder all pins except the modified “+” pin.

Now, when the power jack is secured, you can shape the lead as it shown on the picture below.

Solder the lead to the terminal. Remove excessive flux with an old tooth brush soaked in 99% alcohol.

Here’s a view from the bottom side of the motherboard.

Be very careful. Doing this modification you can damage the motherboard and make it unusable. Proceed on your own risk.

Installing USB Bluetooth adapter inside

Here’s how I installed an external USB Bluetooth adapter inside my laptop case.
My old computer wasn’t Bluetooth ready, it didn’t have the internal connector and antenna for it. I decided to modify my USB dongle and move it inside the case.

I didn’t want to use my laptop with an adapter sticking out from the side.


First of all, I installed Bluetooth adapter software on my computer to make sure everything is working fine while it’s connected to the USB port.

For this modification you’ll need:
1. Laptop disassembly experience.
2. Soldering skills and tools.
3. Inexpensive USB Bluetooth adapter.
This modification is only for experienced users.  You can damage your computer. Proceed on your own risk!
This guide should works for most computers as long as you have enough space to mount the Bluetooth module inside the case.
First of all, I disassembled the case and found a place for the adapter.
In this guide I’m modifying a Toshiba Satellite A105.

My idea was simple. Remove the Bluetooth adapter circuit board and solder it directly to one of the USB ports.
NOTE: after this modification one of the USB ports will not work.

I found some thin wires laying around.
Make sure that wires are long enough for your project.

Disassembled the adapter and remove the circuit board.

Unsolder the USB connector.

The circuit board easily fits into the empty place inside the laptop.

I soldered four wires to the circuit board. I used terminals for the USB connector.

After that I soldered wires to the back of the USB port.

At the last step I installed the Bluetooth circuit board into the case and routed wires to the USB port.
I secured wires to the motherboard with electrical tape.

Finally, assembled the laptop and tested it. There is no on/off hardware switch for the Bluetooth module but I can turn it on and off through software.

Later I found that the reception range wasn’t as good as for external adapter but it was enough for me.

New screen installed but not working

If you installed a new screen into the laptop and for some reason it doesn’t work, there may be a few  things you could have done wrong.
Lets figure out step-by-step how to troubleshoot and  and fix the problem.
First of all, I assume that your new LCD is compatible with the original one. If the screen looks identical, it doesn’t exactly mean it’s compatible. Double check the compatibility between the original and new LCDs.


Troubleshooting LCDs with CCFL (backlight lamp)

The old style screens have a backlight lamp inside and require an inverter board which is usually mounted on the lower part of the display assembly, as you can see on the following picture.

On the following picture you can see how the screen connected to the laptop. Also, check out this display diagram.
The video cable routed from the motherboard to the display through one of the hinges. Somewhere close to the hinge, the cable splits. The wider end connects to the screen (supplies data signal) and another one to the inverter board (supplies power for inverter).

If your new screen lights up but has no image make sure the video cable plugged correctly. It’s possible that during the reassembly process you accidentally pulled the cable from the connector.
Reconnect the cable, secure the connection with sticky tape and test the laptop. There is a chance that now the screen will work properly.

The video cable has to be seated properly, all the way down into the connector.

Some older LCDs have very thin pins inside the video connector as it shown on the following picture.
Take a look inside, make sure there are no damaged (bent) pins. It’s possible that you accidentally bent them while trying to plug in the cable.
You can straighten bent pins with a very small screwdriver. Be careful, they are very fragile.
Fortunately, most newer LCDs have a different type of connector, without any pins inside.

OK, you have reseated all cables but it still doesn’t work. What’s next?
If your original screen was cracked but undamaged areas still work and show some image, you can use it to test the laptop.
Disconnect the new LCD and install the old damaged one back in place. If the old screen still works but the new one doesn’t, your new screen is defective. Send it back to the seller for a replacement.
Here’s another scenario. The new screen kind of works. You can see a very faint image but there is no backlight.
Disconnect the new screen from the inverter board and plug in the old screen instead (I assume it has working CCFL), as it shown on the picture below. If the original screen lights up, apparently the new screen has defective backlight lamp.

 

Troubleshooting LED-backlit LCDs

Newer LED-backlit LCDs have only one cable connected to it. This cable supplies data signal and power for LED backlight.

If your new screen doesn’t work, check the connection first. Make sure the cable seated properly, all the way down into the connector.
You can test the computer with the old, partially working screen, as we did earlier. If the old one still works, but the new doesn’t, your new screen is defective or not compatible.
Also, you might be interested in how to troubleshoot bad video.