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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.
June 29th, 2009 at 2:41 pm
Do you know how to get to the powerjack in an IBM t41 in order to replace it?
June 29th, 2009 at 2:44 pm
samir,
You’ll have to remove the motherboard from the laptop base as it explained in the official service guide. After that you can unplug the defective jack from the motherboard and plug in a new one.
July 5th, 2009 at 8:30 pm
Can you tell me how to remove the frame around the screen? I want to clean behind the plastic covering of the screen, if there is one. I have an IBM T-42. Thanks in advance.
July 6th, 2009 at 9:50 pm
Adam,
Here’s how you can remove the screen bezel. I think that’s exactly what you are looking for.
July 7th, 2009 at 5:39 am
I just had my computer repaired. They initially said it was the LCD screen and charged me to replace that. It failed again within three days and when I went back, then said it was the inverter. After replacing the inverter, they said it was actually both the LCD and the inverter. And that the bad inverter had broken both my original screen and the first replacement screen. Is that possible? It seems from your description above that the two are separate issues. Thanks!
October 5th, 2009 at 11:54 am
Hi,
That’s a valuable information and thank for that. I ahve a different situation. On my T42 screen I have a around 1″ dark verticle stripe. The picture/pixels in that 1″ verticle lines are visible but really dark. Other area of the LCD screen is just fine, bright, crisp picture.
1. Do you think it’s an INVERTER issue?
2. If not inverter, what could be the problem.
3. I am thinking to get another broken T42/40/41 but good LCD and replace the whole cover. Should I replace the whole cover or only take the LCD from good one and replace with BAD one? I am looking for easy replacement, do not want to dismantle too many tiny parts etc.
I will really really appreciate if you can shed some light in my situation. If there are some unforeseen warning/scenerio that I may not know, please advise me.
Thanks again
Sincerely,
Mehdi Anis
St. Cloud, MN
October 5th, 2009 at 12:07 pm
Mehdi Anis,
Nope, this is a problem with the LCD screen. You’ll have to replace the screen.
It’s way easier to replace the whole display assembly without taking it apart.
November 8th, 2009 at 7:09 am
Dear Laptop Tech
I have e little be problem wit my IBM thinkPad T40p….. I buy it when I was in Dubay, from the second hand computer shop.
On computer is not installed OS, I install the Win XP SP3 Rus (Zwer), when the windows find all driwers without problem. only modem and 2 undefined device. but i have problem with keybord.. (on keybort under UIOP buttens written numbers,) when i write the text the words that on this underwritten buttens with number, writted numbers not words.. may be problem with not installed some drivers…
Please Laptop tech…. help me to solve this 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?
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 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.
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?
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.
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!!!
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.
December 29th, 2011 at 12:24 pm
Thanks for your hints. Now the backlight works again.
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 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.