How to replace backlight lamp (CCFL)

posted in: Screen | 274

In this guide I will disassemble a laptop LCD screen in order to remove and replace the backlight lamp (CCFL).
Replacing the backlight lamp is not an easy task even for experienced technicians. If you do something wrong you will permanently damage the LCD screen and have to buy a new one. Proceed on your own risk and do not blame me. :)

Some recommendations before you start:
1. Work in a clean room. You don’t want dust and lint inside your LCD screen.
2. Make notes, so you know how to assemble your screen back.
3. Take pictures.
4. Before you remove something, take a closer look at the part and memorize how it is assembled.
5. When you are assembling the screen, remove dust and lint with compressed air. Do not use cloth.

The backlight lamp (CCFL) is located inside the LCD screen, so we are going to take it apart. In this article I’m not going to explain how to remove LCD from a laptop, it’s been covered before.

LCD screen with bad backlight lamp

Remove sticky tape and foil from the back of the screen and glue it somewhere so you can reuse it later, when you assemble the screen.

Remove tape

Removing tape from the backlight cables.

Release backlight lamp cables

On my screen the green circuit board was glued to the plastic frame with a double sided tape. Carefully unglue the circuit board. Be very careful, do not flex or bend the circuit board.

LCD circuit board

The circuit board has been unglued.

Remove circuit board

Place the LCD screen on the side and start removing the metal frame witch secures the LCD to the plastic frame. There will be many latches on all sides of the frame, you can unlock them with a small screwdriver.

Open latches

Continue separating the metal frame from the plastic base.

Separate LCD frame

On the following picture you can see that frame, LCD with the circuit board and screen base have been separated. Be careful, do not touch internal components with your fingers. Handle all internal components by the sides.

Remove LCD

Place the metal frame and LCD with the circuit board aside. You’ll need them only when you assemble everything back together.


There will be a few transparent layers inside. Carefully remove them from the screen base. Do not separate the layers, just put them aside together.

Transparent layers inside screen

Keep everything organized, so you have no trouble assembling the screen.

Set aside

Start removing the metal cover from the backlight lamp (CCFL).

Remove backlight cover

The backlight cover has been removed.

Backlight lamp cover

The backlight lamp (CCFL) cables are routed through small plastic hooks.

Backlight lamp cables

Unroute the backlight lamp cables.

Release backlight cables

Now probably the hardest part in this disassembly process – removing the backlight lamp and reflector. The backlight lamp is secured inside the reflector so you have to remove both and then separate them.
Before you remove the backlight lamp and reflector take a closer look how it’s assembled and mounted to the screen base. Fitting the backlight and reflector back in place could be a very challenging task.

Remove backlight lamp reflector

The reflector is glued to the screen base with a double sided tape.

Backlight reflector

After the reflector has been unattached from the screen base, you can start removing the backlight lamp. As you see on the picture, I marked the left side of the reflector with a red dot so I know where the red cable goes when I assemble everything back together.

Remove backlight lamp

The backlight lamp (CCFL) has been removed from the reflector.

Backlight CCFL lamp

In order to access the backlight lamp leads you’ll have to remove the rubber caps from both side of the lamp. I’m not sure if you can touch the backlight lamp with your fingers, so I would use rubber gloves.

Remove cover

Cabled on both sides of the backlight lamp are soldered to the backlight leads. In order to access the leads you’ll have to remove the black insulator on both side of the lamp.
Unsolder both cables from the old backlight lamp and solder them to a new one.

Cable soldered to backlight lamp

You can test the new backlight lamp (CCFL) before you install it back into the screen. Connect the backlight lamp into the inverter board and turn on the laptop. The backlight lamp should light up.
From my experience, on some laptops the backlight lamp will not light up until the video cable is connected to the LCD screen. In this case you’ll have to assemble the LCD screen and then test it.

Test backlight lamp

274 Responses

  1. @ chi,

    Hi, can you explain why the bottom of the screen is brighter than the top half after a fresh bulb replacement? This was for a ThinkPad t43 with a LG panel. I did a similar replacement for another t43 but with an idtech panel a while back and it went without a hitch.

    Probably the new CCFL bulb is not aligned correctly or maybe the reflector not aligned correctly.

  2. Hi, can you explain why the bottom of the screen is brighter than the top half after a fresh bulb replacement? This was for a ThinkPad t43 with a LG panel. I did a similar replacement for another t43 but with an idtech panel a while back and it went without a hitch. Thx

  3. cj2600

    @ Marie,
    The new backlight bulb should work outside the case. It doesn’t matter if the bulb is mounted to the case or not.
    You tested everything correctly.
    I think it’s either your new backlight lamp is defective OR it’s not compatible with the inverter somehow (which I doubt).
    I’ve been using the same backlight lamp for years and tested multiple computers and never had any compatibility issues between CCFL and inverter.
    Probably your new backlight lamp is defective.

    Why don’t you replace the entire screen? They are cheap these days. Replacing the backlight lamp is very difficult even though it might look easy on my pictures.

  4. Marie

    Thanks for putting this page together. I was wondering if you could help me determine a defective bulb… Here is my situation:

    I have 2 identical laptops — 1 with a working screen, the other not. On my working computer I can turn it on, and of course the backlight and everything comes on. It is completely normal. I bought a new set of ccfl bulbs with a harness for my non-working laptop screen. Before I experiment with my old laptop, I wanted to verify that the bulbs are working. I opened my working laptop and ONLY disconnected the ccfl plugs that go into the inverter. The rest of everything is in place–motherboard connections, lcd connections, etc. The only difference is the new bulbs and their connectors.

    Well, if I connect the new bulbs to my working computer’s inverter, they flash on for half a second and then go off, never turning back on even when it should be at full brightness. I can follow the boot process with a flashlight behind the screen which shows when the bulbs should be fully bright. I am thinking it may be a problem with the wiring/soldering on the harness…? If I reconnect the plugs from my working bulbs, they come on accordingly. If everything is connected IDENTICALLY, does it make and sense that the new bulbs would not turn on outside of the encasing?? I got inspired by seeing your picture of the bulb on outside of the fixture…

    Thanks in advance for any help… I really appreciate your time.



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