A couple weeks ago I got a call to assist with an iMac that failed to boot into Mac OS X. A quick assessment over the phone gave me enough information to know it's the hard drive which was on its last leg. I took the iMac home attempting to retrieve the data on it and replace the hard drive. It's worthy to note that the iMac was not even 2 years old, very unusual for a hard drive to die in such short period of use.

The moment I had the iMac opened, I knew exactly why the hard drive had such short life. There was dust pilling up every where inside the iMac. Essentially the dust blocked the air flow and kept all the heat trapped inside the computer. The hard drive on these Aluminum iMac is right in the middle of the chassis and arguably take the most punishment from the heat build-up. Luckily though, the hard drive was the only component that failed and not the other crucial parts (which are much more expensive to replace).

So if you have an aluminum iMac at home and in a room without much ventilation, check the bottom vents often to make sure there's no blockage of air flow. A quick way to do so is the tap either the bottom right or left of the iMac and watch to see if there dust particles falling out. Seeing a chunk of dust drops out of the vent is a sign you should call The IT Guy for help immediately. :)