I had disconnected it from everything, as I usually do before I travel, so the stray lightning bolt won't fry it. When I reconnected it, the green power LED on the motherboard came on (the lying bastard) but nothing else did. No CPU, no POST, not even a fan. Ugh.
This PC has been slightly power flaky since I built it, almost four years ago. If it is disconnected from the power line, it refuses to turn on again until you pull the PS2 keyboard and mouse connectors. Then it turns on, and you can reconnect everything. What? It's been on a KVM switch, that draws power through the PS2 connectors. Maybe that was the problem?
This time, though, the trick didn't work. Nothing worked. A little googling around (using my traveling laptop) suggested that it was the power supply at fault. Even with the lit motherboard light? Yep, even with that. And come to think of it, there had been an odd 'burned' smell around the PC for the last six months or so. I had thought dust might be settling into the fins on the CPU cooler and burning up. But I sniffed at the power supply, and yup, strong burned smell.
So. Surf to Newegg for a new PS, a Seasonic M12II 430 watt, well-reviewed by Silent PC Review. Arrived last night. Installed.
And the PC turned on, and acted like its old self. Yes, the problem was indeed the power supply. The evildoer? J'accuse Antec Model SP-400. Which is odd, because Antec is almost as well thought of, as a PC parts maker, as Seasonic. Still, this one failed after less than four years of fairly light use. No whomping gaming cards, no SLI, none of that. It may not be an especially good Antec model. It came with the case. Lesson: don't settle for the PS that came with the damn case. Shell out a little for a good PS.
Something else: the PC had an annoying buzz ever since I built it. A couple of slaps would make the buzz go away, but it always came back. I re-tightened every screw, made sure everything seated properly -- no dice.
With the Seasonic installed, the buzz is gone. The buzz must have been in the Antec PS. Maybe a sign that the Antec was damned in the cradle? A defective unit from the start? Could be.
So my comfortable old Ubuntu box is back in service, and I'm content. But after four years, it's beginning to feel just a little sluggish on some tasks (Firefox, I'm lookin' at you) and I may built a new one around 2011.