I've done some searching but didn't find any definitive answer on this. Does anyone know if there is a certain temperature that causes iMac's to shut down? I have been queuing up a number of movies in Handbrake and letting the iMac chomp away at them. For several months this was not an issue (this is a 2009 iMac 2.93 base model, no upgrades.) For the last week or two, I have come back to find the computer off a number of times. Every time it has done it it was while Handbrake had the processor pegged at 100% for a long time. The 3 highest temps are usually the power supply, the Northbridge and the CPU and the highest I have seen them is right around 70C. Last night I did some messing around with that fan control program and got the fans to run higher while Handbrake was running. I managed to keep all of the temps below 65C. I am going to leave it like this for a while and see if I have any more problems. I'm also going to try to cut back on the number I queue up at a time. I was setting up enough to keep it going for 12-14 hours. I don't actually think it was a time thing though as last night it shut down while my wife was using it and it was less than 2 hours after I started a batch. Has anyone else had similar experiences? I see some people suggesting it could be caused by bad memory, but as mine only seems to happen with Handbrake at 100%, I'm thinking it's just heat. Thanks for any thoughts. I'm hoping to avoid taking the computer in as it's just a hassle.