[skilskilskil]

The G5 iMac I use at work has been acting strange lately for two possibly related/possibly unrelated reasons.

Problem 1: Sometimes during the day if I restart the computer the LCD appears darker near the top and lightens up near the bottom. Shutting off the computer for 5 minutes then restarting usually solves the problem.

Problem 2: Sometimes for no reason I can pin down the iMac will suddenly enter hibernation mode. I've triple-checked the energy-saver settings and any thing else that might cause it but it persists across all accounts. I hope it's just a software issue but my gut feeling says no as I've been using Macs for 10+ years.

Hopefully it's an easy fix. Thanks for any help in advance.

[Big Mac]

Both problems sound very much like hardware ones to me, unfortunately.

[Simon]

Run Apple Hardware Test (it's on the Install DVD, instructions are printed on the label) and see if it reports any hardware errors.