And then nothing turned itself inside-out.

Checked my email this morning and saw that backups of my wife's computer had timed out. Weird, I thought, but didn't look into it further. Then my wife comes out and says, "Hey, my computer's having a stroke.". Uh-oh.

So I have a look and it's constantly, randomly, power cycling. It will get to the Ubuntu splash page then shut off, then get halfway through the BIOS check and shut off, then get halfway through boot and shut off, then stay off for two minutes, then turn on again. WTF?

First thought is cooling, of course. But the power supply feels cool to the touch, and when I get to the BIOS temperature page it says the CPU is at 51C -- eminently reasonable. (Then it shut itself off.) Okay, flaky RAM? Wonky graphics card? Dying, though not from lack of cooling, power supply?

Then it makes it all the way to Ubuntu's login page. I switch to a console and start looking at logs. This thing has been rebooting all night -- as in log messages about how shutdown has been invoked. And then I check /var/log/acpid and I see lots and lots and lots of entries saying that event POWERBTN (or some such) had been receieved, so Ubuntu was executing /etc/acpi/powerbtn.sh and shutting down nicely. And then I saw a broadcast message from root saying that the system was going down for reboot NOW!

Tempted to just try booting w/o ACPI, but I think that would just mask the issue. Back to Google...