Hacks and Gadgets by HJL

This evening I started having the same problem with my Thinkpad T42p as the one I had a few weeks ago with one of the LCD monitors, which is that has started blacking out the backlight at random, typically a few seconds or minutes after starting up the system. In my case, it was easy to determine that the graphics subsystem was working fine, as I normally have an external monitor connected already, which didn’t have any problems at all. That leaves the LCD panel, backlight, and inverter as likely suspects.

I found some handy resources for diagnosing and repairing notebook display problems:

Here is part of an e-book on diagnosing notebook problems, this section is Notebook LCD Display Monitor Problem

Here is an illustrated step-by-step guide to disassembling an IBM T40/T41/T42/T43 display bezel and replacing the LCD backlight inverter.

For now, the temporary workaround is to simply reduce the screen brightness to 6 bars instead of 7 bars. So far this seems to reduce the stress on the inverter and/or the LCD backlight enough that it doesn’t shut down any more.

Twhirl has a handy auto-update feature, which was giving me problems for the past few weeks. Normally, it will  notice that there is an update available and ask if you’d like to install it, but the most recent update (0.8.4) didn’t work. I was getting these error messages:

The application could not be installed because the AIR file is damaged. Try obtaining a new AIR file from the application author

An error occurred while updating the application. Try updating it again. If the problem persists, contact the application author.

After a few tries, I was guessing that it might be an AIR problem; this weekend I finally got around to some computer housekeeping, and downloaded the latest AIR runtime (1.1) from Adobe, after which the Twirl update successfully completed. Some less cryptic error messages would be helpful.

One of the LCD displays on my desk recently started flickering on occasion, and this afternoon started going completely blank. In a quick round of testing, I discovered that the graphic card works fine with other displays, and that the problematic display would actually work for a few seconds immediately after power on before the screen turned black.

A quick Google search shows that this is a fairly common problem among LCD panel displays from many manufacturers, and typically involves a problem with the power supply for the LCD backlight. One fix apparently involves replacement of several electrolytic capacitors in the power supply.

In the meantime, reducing the screen contrast and brightness has temporarily fixed the problem. It seems to be somewhat heat-related.