Question about IBM ThinkPad T21 Notebook

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IBM ThinkPad T21 LCD display very dark

The LCD in my IBM ThinkPad T21 LCD display becomes very dark. I still see the picture, but the image is very weak. Someone in the internet suggests the Inverter problem. So I bought one inverter from eBay and replaced the old one. The problem is still the same. Nothing better or worse. Can someone tell me what the problem is?

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  • DavidWang Dec 29, 2007

    How to fix the backlight?

  • DavidWang Dec 29, 2007

    No. I didn't

  • DavidWang Jan 03, 2008

    I still don't see the backlight. Both on the top and at the bottom of the LCD, I see about 5" wide area are covered at the middle. I don't know how to open it. Do you know where I can get the detailed manual to see assembling of the LCD?

  • eliasib Mar 19, 2008

    I have the same problem, it used to be solved by flipping the display back and forth a couple of times, but now that trick doesn't work anymore. Did you ever solve it for good?

  • shadl Apr 05, 2008

    I have the exact same problem. Do we need a new LCD or something else?



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The problem can be at the flexible cable that connecting mainboard to LCD panel. There are two line that connecting to backlight lamp. The position of the broken cable is in bottom-center of LCD. One or more line/track broken can resulting : LCD blank or LCD display very dark. The solution is : jumper the broken line with jumper cable & soldering.Or you must replace the flexible cable.

Posted on May 15, 2008

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Definitely the ribbon cable! Replaced the LCD screen and the inverter first with no luck. I had a T21 for parts that I got off eBay for $10, best $10 I ever spent. Used the ribbon cable from that one and the problem is solved. Godd luck.

Posted on Feb 23, 2011


I had the same problem with my T21. I also had to close and open the lid a few times in the beginning, but after a while even that didn't help anymore.
So, I took the whole thing apart, and what I expected turned out to be right: the ribboncable going to the display was cracked where it leaves the lid and goes into the pc-case.
It is possible to repair it (I know, because I did) but if you're not used to work with a soldering iron (and your eyes are in perfect shape), don't even try. These contacts are so tiny that I had to work through a magnifiying glass all the time.
First, you have to remove the outer shell of the ribboncable. The easiest way to do that is with one of these highspeed rotary tools. (Note that this shell is made of conductive material, watch out with the debris)
When the cover is removed, you can see which traces are broken. Before you can solder the broken ones, you have to remove the varnish from them. That can be done with a sharp knive. Be very careful, because the copper layer underneath is very thin.
In my case, four of these traces at the side of the cable were broken (varying in size between 1/2 and 1.5 millimeter).
I soldered some copper wires over the fractures, and that did the trick.
It works again!
Biggest challenge now is to get it assembled again :-)

Remark: If opening and closing the lid solves the problem for a while, you can be definitly sure it is the cable, and not the inverter or the LCD.

Posted on Jun 06, 2008

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I had the same problem and the solution was to replace the inverter card located at the screen panel.

Posted on Jan 15, 2008

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The problem could of been the backlight

Posted on Dec 29, 2007

  • Thomas Christopher
    Thomas Christopher Dec 29, 2007

    did you see it when you took it apart?

  • Thomas Christopher
    Thomas Christopher Dec 29, 2007

    It is probably down one of the sides of the LCD screen. The inverter board changes the small dc voltage to ac to run the light.


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I cannot get network connection with my ibm t21 thinkpad .have a wireless router abd my hp laptop is working fi


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ThinkPad T21 dark monitor. What part to change?

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Jul 03, 2009 | Computers & Internet

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You could have a defective LCD screen, If the laptop appears to be running and the hard disk is spinning but the screen is dark then, to determine if you have a LCD screen or video card problem, read this and follow these instructions.
Defective CCFL backlight, it may have the following symptom: Screen flashs on red/pink and off. Picture stays on in red and slowly be come normal. Picture flickering with dim display or appear black. Picture flickering on and off. All these symptoms indicate that the LCD backlight lamp (CCFL Lamp) has reached the end of the life and all you need to do is replacing the CCFL lamp.
Connect an external monitor to your laptop and power the monitor up first then the laptop, if you see the normal Windows images then the video card and laptop is OK and the problem is definitely the backlight. Dim image and/or dark display on the laptop's LCD screen indicates a faulty LCD backlight and it could be the inverter that supplies high voltage to the CCFL lamp or it is the CCLF lamp is nearly burnt out or burnt out, most likely this is the case.
The inverter can be replaced easily but the CCLF lamp is more time consuming and requires soldering skills.
Check out
for parts, repair service and DIY info.

Jun 22, 2009 | IBM ThinkPad T23 Notebook

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Screen is black

If it's still under warranty, IBM should come out & fix it. Call them.

Mar 25, 2009 | IBM ThinkPad T21 2647 Notebook

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How to remove the display on IBM T21 laptop

The laptop screen is secured to the laptop with screws at the hinges.
There are usually two screws per hinge. The LCD screen has one ribbon cable and possibly a power connector for the back lighting attached to the motherboard near the hinges. Disconnect these before you lift the LCD off the base, they are under the plastic panel above the function keys next to the hinges.

Feb 03, 2009 | IBM ThinkPad T21 Notebook

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Back light on ibm t21

This is an known problem I think you must replace the backlight:
look for example ebay partnr: 260327530145
only for example if this is your problem.





- Flickering, red or pinkish hue to display and even total darkness. These symptoms are a result of a failed or ageing backlight or a failed, damaged. This is caused by the defective backlight lamp and all you need to do is replace the backlight.


Our high brightness LCD cold cathode lamp (CCFL) with long life, it is more than 50000 hours, with Japanese new cathode, phosphor, glass, and other materials, they are perfect for all LCD backlight application and other purpose, such as instrumentation, medical devices, and all type devices.

Suit for

Any 14.1” LCD Screen (2.0mm in diameter and 290mm Length) and (2.0mm in diameter and 292mm Length)


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Oct 14, 2008 | IBM ThinkPad T21 Notebook

1 Answer

LCD and inverter replaced, still dark

The most common fault here is certainly the screen cable - it is available cheaply on ebay - I'm in the UK so here is a local example in this link:

T23 Cable

the other slim possibility is failure of the backlight switch which detects when the screen lid is closed.

Please rate this assistance as we depend on your feedback - hopefully this should be fixya - thanks,

Mar 24, 2008 | IBM ThinkPad T21 Notebook

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Cracked TFT screen on IBM Thinkpad T21


46L4843 LCD 14.1

05K9942 LCD XGA 14.1




05K9944 ALL SUB TO 04L2348

Oct 16, 2007 | IBM ThinkPad T21 2648 Notebook

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