Hello. I'd like to share with you my latest Mac experience in the hope that this piece of info will be of some use to somebody.
After four months of flawless performance, today my PowerMac froze to a very bad halt. After shutting it down and starting it again, all I got was three spine-chilling beeps, after which the fans began to rumble at full throttle. Having two computers in my room, I could access the internet and do some reseach; three beeps had something to do with bad memory. Tried to start again, and the computer booted, but hanged during Mac OS X startup. Finally got to start Mac OS X, but after some time it hung as well. It smelled like memory problems.
I decided to ignore Apple's Technical Support Service and fiddle around with the memory modules for a while, by myself (always remember, children, to unplug completely the unit, make sure you discharge any static from your body and not to touch the metallic terminals before diving into the belly of the Beast). To cut a long story short, I just removed my two 512 MB modules and fitted them into their slots again, and that's how I fixed the glitch!. So remember, children: quite often, hardware faults are due to an improper connection or some other silly matter; you might want to tighten all connections and screws before sending the machine for servicing.