I'm using a 2010 I7 27 inch Imac with Snow Leopard, no extra ram installed, and then today it just suddenly shut down with no warning. I wasn't pushing it that hard (sometimes I have lots of browser windows open, but didn't have that many today) and then I was just looking at something and it just suddenly switched off. I turned it back on a few minutes later and everything seems fine, but I'm still worried about the sudden shutdown especially as my regular warranty is ending soon. I bought it back in mid-August of 2010, so my one-year warranty is almost up, so I'm wondering if I should try haul it in to a Genius bar just to have it checked out just in case (although I'd prefer not to since its heavy) or maybe go buy Apple's extended warranty just in case something else happens in two months (still getting the occasional e-mail nagging about that). Does the one year warranty end exactly one year from when I bought my Imac or the end of August? The back of my Imac has enough ventilation I think, although the computer is usually somewhat hot anyway, but not super hot (although I don't have anything installed to record the temperature so not entirely sure), and it isn't that scorching hot here right now, and I even turn it off every night just in case. I might've jostled the power bar a bit in the hour before it shut down, but its not the first time I've moved the power bar much more with nothing happening, so it seems odd that that would cut the power. If it is a power supply problem, could I just take the cord into an Apple store and exchange it there? Or maybe I should try moving the cord again and see if anything happens? It has only happened the one time so far, and it turned on again normally (posting from it now), but I don't want my Imac to just die a few days after the warranty ends. I'll probably just wait and see but checking first to see if there is anything else I should do. Hm, probably should update my Time Machine backup (although the last back-up was this month) just in case. Or maybe I'll run Software update, forgot to update a few things for a while.