I had an interesting experience when Baton Rouge had snow and ice a couple weeks ago. Our power got knocked out for a few hours, a longer time than the UPS’s were capable of handling.
The first warning of trouble was when I got home from work. My wife told me that he had turned off the power controller to my desktop computer because it had an alarm going off. (She was right, too.)
All I had to do was turn on the power to the desktop and its internal alarm would start beeping. Well, that’s too mild a word — the beeps were quite loud and abrasive. Plus, the computer wasn’t running.
It wouldn’t run, either. I could press the power button and the fans would whirl for a second or so, but then the computer would shut down — the alarm would keep going, though.
I tried disconnecting the power cable and reconnecting it. No luck.
Then, I unplugged it, disconnected all the hard drives and took out everything but the video card and memory. I plugged it in again — No luck. The alarm started after a few seconds.
Oh, by the way, the Abit (brand) motherboard has this nice alphanumeric indicator to show which error code was triggered. The code wasn’t in the manual.
I unplugged the computer and then used the CMOS jumper to clear the CMOS memory (where the BIOS settings are stored). Plugged it back in. No joy.
Finally, I did one more thing. I unplugged the computer, took the battery out of the motherboard, and then used the jumper to clear the CMOS memory.
I plugged the computer back in. It worked. I shut it down. I plugged in the PCI cards I had removed and hooked up all the hard drives. I powered it on — and it worked. YEA!
About that time, I remembered that I done the same thing with my Linux desktop a couple years ago, after the Hurricane Katrina power outage, when it would spin the fans and then stop. Different computer, but similar symptoms — and clearing the CMOS after removing the battery solved it.
This is strange, though. You shouldn’t have to remove the battery to get the CMOS jumper to clear the CMOS memory. But, that’s twice that this little trick solved the problem.