After 30+ years with PCs, I was given a non-working iMac. Decided the hd was at fault and replaced it following the instruction online. It's now up and running. Hooray! I've noticed that my iMac, (early 2009 24") runs really hot. Checking the sensors I find that the power supply is running at 176 degrees F. Logic board at 126F and the Northbridge chip and heat sink are at 165 & 156F. Just wondering whether this is considered normal. Any thoughts on the subject will be appreciated. Thanks for looking.