Unexplained, random power offs.
Over the last week or so my iMac has been randomly powering off. Especially at moments when I've written really well formed paragraphs for my master's thesis, yet before OpenOffice has auto-saved. I've checked the console log and there does not appear to by any particular software issue related. My guess is a bad power supply.
Has anyone else had a similar problem or suggestions for diagnosis? I'll probably try a fresh install of OS X before I drop $120 on a new power supply, but I'm not sure that will help. I haven't made any major changes to the OS or the iMac in the past couple of months. The HDD was upgraded to a 1tb about 6 months ago and the superdrive needed to be replaced about 5 months ago.