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.

LCD

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. Dexter

    I have a LCD which is built and looks exactly like the one above. (do they all look the same?????)

    My problem is that I have a horizontal line running across the screen.

    I dismantled the LDC, but it seems that the LCD has leaked (?) at the edge where these lines appear. Can this be correct ? I can send you some pictures if I have your mail id.

    Any help appreciated.

    Thanks.

  2. cj2600

    Steve Yaroscak IV,

    My problem however is that everything seems to be working great I just can’t see anything on the screen that is working because obviously the bulbs out.

    Can you see a very dim image on the screen? Any image at all? Did you try replacing inverter before replacing backlight lamp?

    When the backlight stops working I usually follow these steps:
    1. Check the lid close switch to make sure it’s not stuck inside the laptop case cutting off power from the inverter board.
    2. Reseat cables on both ends of the inverter board.
    3. Replace inverter board.
    4. Finally replace the LCD screen. I do not replace CCFL lamps for my customers, I do it only on my own laptops. It’s very time consuming repair.

  3. cj2600

    Anthony,
    Search on Google for companies selling CCFL lamps for laptops, here’s one: lcdparts.net
    After that contact them and explain what you are looking for. Most likely they will help you to find CCFL for your screen.

  4. Steve Yaroscak IV

    Hello. Looks like you’d be the one to ask about this.
    I’ve only looked at your bit on how to replace a ccfl
    and to reach it to do so. My problem however is that
    everything seems to be working great I just can’t see
    anything on the screen that is working because obviously
    the bulbs out. I took everything apart and ordered a new
    lamp on EBAY but after soldering and testing it as you show,
    the damn thing isn’t doing anything. The laptop is a Gateway
    4542GP. And it is my parents. I used it for a week and it’s
    my ass if I don’t fix this sucker! How can I test the bulb W/O
    the inverter? I don’t have a voltmeter well it’s not working
    itself so I’m kinda screwed as far as testing that right? The
    voltage required for the bulb is A/C right? Please Help!!!!!!!

  5. Anthony

    How can I find out the part number for a lamp for Fulitsu Lifebook C2210? This is a 15 inch screen and has a Cold Cathode Fluorescent Lamp. The part number for the screen is LTM15C460F (or CP121857-02)……Thanks

  6. Wayne Reep

    I’ve already removed the ccfl but cannot find where to buy a new one. I have a Toshiba satelite bought in 2005.

  7. That helped me to replace backlight for my old laptop. Thanks a lot.

  8. Hello there,
    I have a problem with my laptop, the back light seems likes is not getting electricity from the inverter.
    I bought a new CCFL lamp and connected to the Inverter output. When I turn on my computer the lamp turno on for like half a second and then it turn off, and it did that like 3 times, and after that it never turn on again.

    So my question will be, is the back light turn on all the time when you connect a new one?
    And with the monitor connected, is the lamp turn on always?

  9. coolerro

    do you know at what voltage the backlight lamp works?

  10. thank you for the instruciton how to replace the backlight of my laptop, it help me a lot, i appreciate that.

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