How to Service Broken Keyboard Connector on Laptop

This guide explains how to fix a broken keyboard connector on a laptop motherboard. I do not claim that my instructions will work for any connector type in any laptop brand, but if I can help a few people, I can call my mission accomplished.



Let’s say the keyboard in your laptop stopped working properly and you decided to install a new keyboard yourself. You disassembled the laptop, removed the keyboard, tried to unlock the keyboard connector and… OHH! MAN!… a piece of the locking clip on the connector got broken!


What can you do? Unfortunately, you don’t have a lot of options. The keyboard connector is permanently soldered to the motherboard and cannot be replaced at home. If the connector was damaged, you’ll have to replace the whole motherboard, use the laptop with an external USB keyboard, or…. try the following trick. Hopefully it works or you.



The keyboard cable is locked inside the connector on the motherboard. In order to remove the keyboard, you have to unlock the connector and release the cable.


On the picture below you see one of the most common connectors. It has the base (white in my case) and locking clip (brown in my case). The keyboard cable is jammed between the locking clip and base.
To unlock the connector, you have to move the locking clip about 2 millimeters in the direction shown by two yellow arrows.

IMPORTANT! The locking clip must stay attached to the connector base.
After that you can pull the keyboard cable (green arrow) and remove the keyboard.



If you are not careful enough, you can move the locking clip too much and break it.
On the picture below you can see the locking clip is missing the left hook.



On the next picture both sides of the clip are broken.



IMPORTANT! Do not though away the broken clip even though it looks completely useless.

If you insert the cable into the connector and will not lock it with a clip, the cable will not make good contact with pins inside the connector and the keyboard will not work.



Here’s how to install the broken clip back in place and make it work.
Position the broken clip the way it was before. In my case both sides of the connector are broken. What could have been worse?



Carefully insert the keyboard cable into the connector. Note, in this type of connector, the cable goes above the locking clip.



Carefully push the broken clip back in place. You can use a small screwdriver to push on the clip behind the cable.

The clip fits tightly when there is a cable inside the connector.



Secure the connection with sticky tape and you should be good to go. The keyboard should work just fine.



The keyboard connector shown on the following picture is very similar to the previous one. 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 keyboard 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 the right side of the clip is broken. But you still can use it!



Insert the keyboard cable into the connector, position the broken locking clip correctly (behind the cable in my case) and carefully push it in.


Even with a broken clip the cable will make good connection with the base and the keyboard should work.



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



If this trick worked for you, it means I just saved you a few hundred bucks on the motherboard replacement.

Read More

How To Troubleshooting Laptop With Backlight Failure

This laptop came for repair because of the LCD screen backlight failure. My customer complained that the laptop LCD screen is black but the laptop works with an external monitor.



Here are my steps for troubleshooting this laptop with the backlight failure.

First of all, I tested this laptop with an external monitor connected to the VGA port and the external monitor worked absolutely fine. I was able to get crystal clear image on the external screen even though the internal screen didn’t light up. If the external screen works fine, then most likely there is nothing wrong with the video card.

Notebook display assembly diagram

After that I took a closer look at the laptop LCD and noticed that the screen is not completely black. The laptop screen still works but the image is very very dull, you barely can see it. It means that the screen still gets data signal from the video card, but for some reason the backlight lamp doesn’t work.
From my experience I know that this problem can be related the lid close switch, faulty inverter board or bad backlight lamp. I checked them one by one.

If you have a similar problem, make sure the lid close witch moves freely. The lid switch is a small button located close to the LCD screen. This button triggers the hibernation or sleep mode when the screen is closed. If the lid close switch is dirty, it might get stuck inside the laptop case and cut off the power from the inverter board. The inverter board works as a power supply for the backlight lamp and if there is no power coming to the inverter board, the backlight lamp will not light up either.




In my case the lid button worked properly, it didn’t stuck inside the case. When I was pressing on the button very fast, I was able to light up the screen but only for a fraction of a second. The image wasn’t bright and it had a pinkish tone. A pinkish tone usually indicates a problem with the backlight lamp, not the inverter board.



Even though I suspected the backlight failure, I decided to test this laptop with a new inverter board just in case. But it didn’t help. The screen didn’t light up even after I replace the inverter board. So, I was right, this problem is not related to the inverter board.



Finally, I disconnected the screen backlight lamp connector from the inverter board and connected my test backlight lamp (I removed it from another cracked screen). For the test purpose, you can buy a new backlight lamp here. Try to find a backlight with the connector already attached to it, so you can plug it into the inverter board. Make sure the connector on the backlight lamp is similar to the connector on your LCD screen.



As soon as I turned on the laptop, my backlight lamp lighted up. Yep, that’s the problem. The laptop screen has a faulty backlight lamp.

Here’s another laptop with backlight failure

This laptop video fails in a little bit different way. In this case the backlight lamp hasn’t failed completely.



The laptop starts with video on the screen but the background has reddish tone, the screen flickers and it makes noticeable buzzing noise coming from the backlight and inverter area. After a few minutes the backlight turns off by itself and the buzzing noise stops. When the backlight is off, the image on the screen is still visible but it’s very dark.



I removed the screen bezel and connected my test backlight lamp.


My test backlight works absolutely fine. The lamp doesn’t flicker and there is no buzzing noise. So, this laptop needs a new backlight lamp.

source : http://www.laptoprepair101.com

Read More

How to troubleshoot laptop battery charging problems

In this post I explain how to troubleshoot laptop battery charging problems. I will list most common battery failure examples and suggest some troubleshooting steps.

Example 1.

Laptop detects the battery but shuts off when AC adapter unplugged.

When you move the cursor arrow over the battery icon while the laptop is connected to AC adapter, it show the remaining battery charge and says “charging”.




The batter power meter utility (if available) also shows that battery is connected and charging.



But… as soon as you unplug the AC adapter, the laptop shuts off completely.

Possible problems:
1. The battery not seated correctly. Try reconnecting the battery.
2. The battery contacts got dirty or oxidized and the battery is not making good connection with the motherboard. Try reconnecting the battery a few times.
3. If reconnecting the battery doesn’t help, most likely the battery is bad and has to be replaced.
4. If you replaced the battery but the problem still exists, this is motherboard related failure. Apparently the battery charging circuit has failed. In this case the whole motherboard has to be replaced (or repaired on component level).

Example 2.

The battery not detected by the laptop.

The battery is installed and you know it’s connected correctly but there is a red cross on the battery icon.



If you move the cursor arrow over the battery icon, it says “no battery detected”.

Possible problems:
1. Most likely the battery is bad. You have a very good chance to fix this problem by replacing the battery.
2. If replacing the battery doesn’t help, this is motherboard related failure. The motherboard has to be replaced (or repaired on component level).

Example 3.

The battery discharges very quickly after it reaches some critical point.

The battery detected by the laptop and charges properly to 100%.
When you unplug the AC adapter, it take normal time to discharge until some critical point (let’s say 80%) but after that the battery discharges very quickly to 0%.

Possible problems:
This is battery related failure. The battery is bad and has to be replaced.

Example 4.

The battery charges only if the power plug positioned correctly.

You have to wiggle the power plug in order to charge the battery. After you find the right position, the battery charges properly.



Possible problems:
1. AC adapter failure. The AC adapter power cable is damaged. You can test your AC adapter with a voltmeter.
2. If the AC adapter works fine, most likely this is power jack (connector where you plug power adapter) failure. In this case the power jack has to be replaced.
In some laptop models the power jack is not soldered to the motherboard, it’s attached to a power harness.



In this case, you can unplug the failed power jack from the motherboard and replace it with a new one.

source : http://www.laptoprepair101.com/laptop/2010/07/21/troubleshoot-laptop-battery-charging-problems/

Read More

How ToTest LCD Screen Inverter in a Laptop

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



If you suspect the inverter board failure, I know only one reliable way to test that. It’s either replacing the inverter board with a known good one and see if it works, or connecting a known good backlight lamp and see if your presumably bad inverter lights it up.


In most cases I go with the second method – testing the laptop with a known good backlight lamp. Why? Because backlight lamps are pretty much universal. The same backlight lamp will work with many different inverters as long as they have matching connectors. I’ll talk about these connectors later.



The inverter board is located inside the display panel under the LCD screen. In most laptops you can access the inverter board if you remove the LCD screen bezel. The inverter board has connectors on both ends. The left side of the inverter is connected to the LCD cable. The right side of the inverter is connected to the backlight lamp which is mounted inside the LCD screen. Check out this display diagram.
To make sure that inverter board is getting power from the motherboard (via the LCD cable), you can test it with a multimeter. In my case I connected the “+” lead of the multimeter to the pin 1 on the connector and the “-” lead to the ground trace around the screw hole. I got about 19.4V DC on that side of the inverter, so it’s getting power from the motherboard.

WARNING! If you accidentally short something on the inverter while testing it, you can damage the inverter or even the motherboard. Proceed on your own risk! Not sure? Don’t do that!



So, the inverter is getting power from the motherboard, but the screen is still dark. Apparently, it’s either bad inverter or failed backlight. Let’s test it with a known good backlight.

Here’s what I’m going to do:
1. I will unplug the LCD screen from the right side of the inverter. Basically, I’m unplugging the LCD backligth lamp which is located inside the screen.
2. I will plug in my known good backlight lamp which you can see on the picture below. Please notice that my test backlight lamp is shorter than the screen, but for the test purpose that’s OK.

Results I’m expecting:
1. If my test backlight lights up, the backlight lamp inside the screen is bad and there is nothing wrong with the inverter board. If that’s the case, you’ll have to replace the LCD screen or replace the backligth lamp (which is not easy at all).
2. If my known good backlight lamp stays dark after I turn on the laptop, most likely we have a faulty inverter board. If that’s the case, you’ll have to replace the inverter board and it’s relatively easy.



 There are two different types of backlight connectors, you can see them on the picture below. The top one (big) is not as common as the bottom one (small). I do most of my test with a backligth lamp which has a small connector.

IMPORTANT! If you decide to buy a new backlight lamp for test, you have to make sure that the connector on the lamp matches the connector on the inverter. Very often backligth lamps are sold without any wires attached. If you plan to use this backlight as a test equipment, you’ll have to find one with wires as I have on the picture 3.

You can buy a cheap backlight lamp with wires here.




Finally, when you ready to test the laptop, unplug the LCD screen from the right side of the inverter.



Plug in your test backlight lamp and turn on the laptop.



In my case, the backlight lamp lights up, so the inverter board works properly.

source : www.laptoprepair101.com

Read More