I opened it up, dusted it out, made sure all the internal power and data cables were secure, and yanked out the old CD-RW which hasn't worked properly in three years.
I plugged it back in, turned it on... and got nothing but the case lights. No BIOS screen. Nothing.
Just to see if the video card was screwed up, I unplugged one of the monitors from the card and plugged it into the onboard video (which was a workaround when I was having all the troubles with the Card From Hell that never did work in this machine).
I cycled the power button rapidly several times.
That had an effect: It now does nothing when I press the power button. Not even case lights.
That particular problem might just be a loose wire in the case power switch.
Or it could be the power supply.
The other problems I've been having make it almost certain that there are hardware issues besides a bad on/off switch, but whether they're in the power supply, the RAM, the motherboard, or the shiny new hard drive I just installed along with Ubuntu... I have no way of knowing.
And, in all likelihood, the problems in one part of the system have probably CREATED problems with the rest.
New Motherboard, at this point, means New Computer, since the old RAM and the old video card are obsolete.
And now, a Public Service Announcement.
"Doctor, it hurts when I do this!"
"Well, don't do that!"
If someone posts something saying that they're having trouble with Linux, comments to the effect of "Don't use Linux!" are not helpful in any way, shape or form.
I was very careful to phrase the first paragraph of my last post as "I don't know how to do X, and can't find any information on it", rather than "this doesn't work in Kubuntu."
That's because I want to learn this stuff. It's complicated, and it's kind of a pain in the ass, and the documentation is about as clear as sixty centimeters of reactor shielding, but I wouldn't be messing with Linux in the first place if I didn't want to learn new things.
At the moment, that's trumped by the need to have a computer that I can use comfortably for several hours at a stretch, looking for work and learning new work-related software. (The Transnote does not qualify. Squinting at this tiny screen gives me a headache.)
Once I find a Real Job (read: not consulting, most especially not consulting in a job that expects me to have my own hardware, I can take the time and effort to learn the ins and outs of X-Windows Configuration Scripts.
I should also note that Ubuntu installed seamlessly and is running smoothly on my grandspawn's system -- which is theoretically older, slower and more abused than my own.