The AppleCare support staff (phone support) have been very knowledgeable and helpful, except for not knowing about the authorized service center in northern Colorado (see previous post). Eli helped me yesterday with 2 useful tools I thought I'd share today for anyone else having problems with their Mac.

The first tool is the standard Apple Hardware Test (AHT). He had me get to it by inserting the Applications disk that came with the iMac, then restarting the computer. As soon as it turns to a black screen press and hold the "d" key. It will eventually bring up the Apple Hardware Test. If it fails, it will return an error code the Apple service people can decode, in my case a "hard drive sensor mis-reporting". You can learn more about this on the Apple site: http://support.apple.com/kb/HT1509

The second tool is actually not an Apple-authored piece of software although it is found on their website, and it's quite useful. It's a Dashboard Widget called iStat Pro. This handy little app displays such useful things as the temperature of your computer, your fan speeds (mine were increasing constantly), CPU and Memory resources and more. http://www.apple.com/downloads/dashboard/status/istatpro.html