Has all the symptoms of a bad PRAM battery, but a new battery didn't help. Computer powers on with no chime. Fan runs. Monitor recognizes power. Typically the screen remains black, but ocassionally will illuminate with the standard gray, and go no further. Hard drive makes a few normal sounding clicks, then goes silent. On one occassion I noticed the mouse trying to come to life, and was able to boot the OS by resetting the PRAM. Strangely, there was no system folder on the hard drive (which includes all control panels), everything was in black and white, but it otherwise seemed to function. Disk drive worked ok. I have not been able to get it to boot since. Replaced the PRAM battery with no effect. If the hard drive was fried, wouldn't it at least boot to the blinking question mark? Any tips on where to go next with this?