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Here are instructions for replacing screen inverter in IBM ThinkPad T40, T40p, T41, T41p, T42, T42p series laptops. All these models are identical and share the same disassembly steps.
What is the screen inverter in a laptop computer? Why would you want to replace the inverter?
The screen inverter is a small circuit board witch is located inside the laptop display panel, you’ll find it below the LCD screen. The screen inverter provides high voltage AC power for the backlight bulb (CCFL) and because of that the image on the screen is bright. If the inverter board fails, the LCD screen remains dark after the laptop is turned on and the image on the screen is very dark, almost invisible. You still should see the image on the screen under a bright light but without backlight the laptop is unusable.
How to fix this problem? Disassemble the display panel and replace the inverter.
Will it fix your problem? Most likely yes.
Why did I say most likely? Because this problem also can be related to the backlight bulb witch is located inside the LCD screen. If you have a faulty backlight bulb, replacing the inverter board will not fix the problem. You’ll have to replace the LCD screen or the backlight bulb inside the LCD screen.
Most common symptoms of a faulty screen inverter:
1. The laptop start as usual but after some times the screen goes black. The image is still on the screen but it’s very dark.
2. The laptop turns on but the LCD screen is dark all the time. The image is still on the screen but it’s very dark. The laptop works fine with an external monitor.
Not sure witch inverter to buy? Find the inverter part number on the page 190 in the service manual.
December 30th, 2011 at 11:44 am
@ gus,
I really cannot tell what’s going on because I don’t know if your new parts were good. Also, I don’t know if you installed them correctly.
Let’s assume all three parts (cable, CCFL and inverter) are good and installed correctly. If this parts do not fix the problem, there must be something wrong with the motherboard.
December 29th, 2011 at 6:53 pm
ok i replace the lamp then i had rum lcd ribon cable problems i thought so i replace that too, then i thought my lcd converter was damage because wen i connect it all the war in it turns off and barely try to connect it like barely touching it works and it lights up, do u know what is what i need then? i already replace the lamp the lcd cable ribon and the lcd converter and now it works only wen i barely connect the inverter to the lcd cable?
thank you
December 29th, 2011 at 12:24 pm
Thanks for your hints. Now the backlight works again.
June 28th, 2010 at 2:08 pm
edsn salnas,
They don’t work at all or type wrong characters?
Make sure the keyboard cable is properly connected to the motherboard. Try reconnecting the cable. Unplug it from the motherboard and plug back in. Test again.
June 28th, 2010 at 2:03 pm
hello tech,
my issue is my UIOP letters dont work at all after removing keyboard for cleaning. pls help!!!
February 10th, 2010 at 9:18 pm
Phantom,
Not sure if you can do that. I guess it’s possible if you know how to write new software for the BIOS and how to reflash the BIOS with your software.
February 10th, 2010 at 6:01 pm
is there a way to put my own information as the boot/welcome on My computer? instead of like the IBM ThinkPad , and put my name in there instead?
November 9th, 2009 at 11:00 am
bahtiyar,
If the laptop gives you a blue screen error after installing the video driver, it’s possible that the video card is bad.
Make sure you are installing the correct video driver.
November 8th, 2009 at 9:52 pm
Dear Laptop Tech
I have one problem more, when I installed the Windows, on first start, my ThinkPad is not start (all drivers of devices founded and installed by Windows itself). There come Blue Dath Screen. Than I start to install another Windows without drivers. After I install drivers for all devices one-by-one with restarting after installing, but when I install driver to video display adapter, after restarting the Blue Dath Screen is coming again.
At present time I work without installed Video Adapter, windows work by Plu-Play foundet adapter.
Is the problem dependet on my devices or driver??
Please help to solve the problem, and thanks for your help with my last problem.
thanks for your cooperation….. and forgive me for my little english
BYE
November 8th, 2009 at 9:59 am
bahtiyar,
I guess instead of letters U, I, O, P the keyboard types 4, 5, 6, *, right?
Also, instead of letters J, K, L, M, it types 1, 2, 3, 0.
It happens because you have NumLk enabled on the keyboard.
Here’s how to fix it on a ThinkPad laptop. Press and hold down the Shift key and at the same time press once on the NumLk key in the top row. No it fixed, isn’t it?