I need to replace (or disable) my lid switch - the one that turns off the lcd when the lid is closed (it's under a little rectangular opening at the right/top of the keyboard). I have the "IBM Mobile Systems ThinkPad Computer Hardware Maintenance Manual" pdf, but this part is not covered. Can anyone direct me to a site where I can download the instructions I need? Or tell me how to proceed. I'm not afraid to "get under the hood", but I'd like to be more prepared than I am. Thanks!

There are no instructions for this.
Remove keyboard and palmrest/KB-bezel.
You should now see the switch on top of the LCD cable.
Using a tiny screwdriver or an Xacto knife , you should be able to 'pop off' the switch.
When removed, you will see the old contacts.
Jumper them by soldering a small wire across them. Don't burn the cable!
Should that fail, replace the whole LCD cable.

First, let me thank you for responding so fast. BTW, you've been a terrific help in the past.
Before I saw your response I decided to yank out the keyboard and have a look. I realized that the bezel would have to be removed as well and decided to wait. Once I got the keyboard back on I booted up and have not had any screen blacking since. I even installed a complete OS on another HD I had and still am looking good. Could just doing this have "fixed" things? Seems odd. I don't need this unit so I will probably eBay it. I just didn't want to sell it if it was still having issues so I will wait a few days and keep testing it. Amazing!

The last T30 that I owned was kind of like that, the lid switch would stick sometimes. But, all it usually took to break it loose was a little tapping or prying on the switch button on the bezel.

I already advised him in another post, to 'hammer' the poor li'l switch...