T23 - Blank Screen Issue, Motherboard?

[Prager34]

As a hobby I've been repairing IBM Thinkpad's for the last several months. I specifically have been working with T23's.

Recently I've been having some strange issues with some of my LCD screens. I'm not so sure that the screens are the problem but I was hoping you guys could help.

I put together a laptop where everything had been tested to be working. The laptop powered on and the screen came up like normal. After I turned it off, the next time I turned it on the LCD screen was blank.

I decided to test the LCD with another T23 and it worked just fine. When testing another working LCD on the problematic laptop, that LCD didn't work either.

I'm assuming that the problem isn't the LCD screen since the screen worked fine on another laptop. I'm assuming that this could be a motherboard issue.

Any ideas of what could be causing this problem and how I could fix this? Has anybody had this type of problem before?

Thanks

[Harryc]

Check the lid switch on the front right of the keyboard bezel.

[Prager34]

I checked the lid switch and the LCD screen still stayed blank. Good suggestion though, I hadn't thought of that.

[Robbyrobot]

You might take a look at this. I found that checking and if necessary repairing the display cable restored the backlight in two cases.

[kkd999]

Robbyrobot, you made a truly user-friendly post about correcting the problem. Thank you! I have the same problem, but I do not have the technical know-how to replicate your solution.
I suppose I could just purchase a used T23 display cable that is known to work and replace it or have an expert replace it. Do any of you have any insight where I could find such a thing and how much it might cost? (I have friends in America and Europe who can bring it to me in India.)

[RealBlackStuff]

You need to download the Hardware Maintenance Manual for your T23 here
With the help of that, and a small philips #0 screwdriver, you should be able to take your complete TP23 apart.
Cables can be found on eBay for ca. $15-20.
Make sure you get the correct T23 cable, there is one for a 13.3" screen (P/N 27L0562), which is rather rare.
For the more common 14.1" screens there are two cables,
XGA (1024x768) with p/n 27L0640 and
SXGA+ (1440x1050) with p/n 27L0590 (also quite rare).
Those cables are NOT interchangeable!