As I previously reported, my old laptop, aramis, got rained on and sustained water damage resulting in--lo and behold--not a dead computer. In fact, most of it was fine, it even booted into X, and all of its components were usable, it would just always crash after around 15 minutes. That led me to believe that maybe, by switching out the mainboard, I might obtain a usable machine again.
Putting that plan into practice, I downloaded IBM's maintenance manual for the laptop, which, for the record, was an IBM Thinkpad A-Series A21m, and looked up the "FRU" (Factory Replacible Unit) number of the mainboard, which, in my case, was supposed to be 08K3264. These boards were hardly to be found on ebay and were hideously expensive, whereas a good bunch of cheaper boards labeled with FRU 12P3156, which suppposedly are compatible with ThinkPad A20 and A21 models, were readily available. I was unsure, but decided to take the risk--given that the 12P3156 board cost only $44.
After two nights of rather nerve-wrecking work on the laptop, I can announce that it is functioning again. :D The difference between the two boards types seems to be only that the one I had (which turned out to be FRU 12P3288) had a header for TV-Out, whereas the new one didn't. Big deal. I can use my 800 MHz CPU on it, and as far as I can tell, it is being run at full speed.
It turns out that my old board had some visible corrosion damage that probably caused the trouble I described above. If I had taken my laptop apart right after the water came in, it might have dried and thus been rescued right away. May this be a lesson to whoever has to do this next. :)
Summary: When buying laptops, buy IBM! Why?
That said, I'm not sure Lenovo is going to do as well, but I hope so.