Dead Thinkpad or attempt repair?

[Rex]

Hi there,

I have an IBM ThinkPad T20. Recently, the screen (backlight?) has not been coming on when booting, but with a bit of tweaking, it does.

Figured that the least expensive option was to replace the LCD screen cable, which I have done. This involves quite a bit of dismantling the computer, but not actually doing anything to the system board, apart from unplugging a few items.

Now, the backlight does not work at all though there is a ‘ghost’ of an image of the IBM splash screen. This is followed by two beeps and the computer switches off.

My questions are; given that it is an old (but good) computer, is it worth throwing good money after bad by replacing the whole screen or just replace the entire computer?

Is the backlight problem likely to be the inverter? What does the inverter do?

The IBM error codes (two beeps) suggests System board problem, check the on-screen error codes, which I cannot see because the screen is not working. The IBM guides lists a POST problem, with EEPROM checksum not being correct.

I have dismantled it a second time to reset the connections, but still zilch.

The current screen is an XGA. Can I upgrade to a SXGA (or whatever the acromyn is) or is this not a wise move?

Grateful for any advice; many thanks in advance,

Rex

[tfflivemb2]

You can attach the T20 to an external monitor, so that you can see what the boot errors are. That will help you determine the problem, and whether or not it is worth investing more time and money into it.

Keep in mind that if the errors involve too much work/money for you, you can always try to sell it here. People are always looking for "projects".

[Rex]

Gentlemen,

Many thanks.

I'll connect it to an external monitor tomorrow and post back.

Can't believe there is a system board problem, for as far as I am concerned, it has not been directly disturbed.

Rex

[Rex]

Many thanks for the external screen advice.

The non-booting problem seemed to be because having removed the system battery; the date and time were reset to zero. Fixed that and the T20 booted on the external monitor. So it’s not a system board problem.

The problem is with the LCD screen itself. Looks to me like the backlight, as there is a ‘ghost’ pixel image. Have recently replaced the LCD cable so I think I can rule that out.

Is there any way to self-test the inverter? Or are the backlight fluorescent tubes likely to be the problem?

Again, many thanks and grateful for any input.

Rex

[rkawakami]

Is there any way to self-test the inverter? Or are the backlight fluorescent tubes likely to be the problem?

I don't believe that there are any self-tests that you could perform to verify that the inverter is working correctly or not. If you have a voltmeter you could possibly determine whether or not the 500v (or more) is being generated to the plug/cable that is going to the CCFL lamps in the display, but you better know what you are doing if you don't want to be shocked.

Yes, it's possible that your problem is a bad tube. Most times they tend to announce their impending departure by a reddish tint however. If yours just simply stopped working one day, then I would say try replacing the inverter. It's fairly cheap to pick one up on eBay or you could try here in the Marketplace forum. You said you have disassembled the laptop so it should be no problem for you. If you don't already have one, download a copy of the hardware maintenance manual (HMM) for your T20 from here:

http://www-307.ibm.com/pc/support/site. ... IGR-4UYM3F

From looking at pages 157-159 of the HMM, your interver board should be an IBM FRU 10L1402. You had mentioned earlier that with some "tweaking" the LCD does (did) come on? Exactly what was done?

It's possible that even with replacing the inverter and the LCD you still won't get any light. This has happened to me with a 600E system that I have. It takes about 5-7 minutes before the lamp finally fires, and that's after I've replaced both items. I'm beginning to think that it's something on the motherboard which is preventing the inverter to work (for awhile).

[HappyHourSC]

Let me know what you plan to do with your notebook. I'm looking for a systemboard and processor. I really want to upgrade it but at this point, I just want to get it up and running.