Sorted out a problem on the main PC - it wouldn't boot up this morning (the fans would come on for a second, then everything would stop, then fans would come on again for a second, repeat ad nauseum).
Did some browsing to fault find, and most googles seemed to think it was a mobo or power problem, so I tried the power problem options (unplugged various bits inside the PC to reduce consumption to see if it would start), but nada.
Kept searching the web, and found a link that said it might be the CMOS battery - took it out, put it back in, and hey presto, everything back up again.
As an additional benefit, I removed 3 years and 8 months of dust from the inside of the computer....
