Winston MacKelvie said: >Anyone have a clue as to what would cause my one piece iMac G5 with >10.4.5 to suddenly click and shut off at random times. Could be >during launch or 10 hours later or even when not being used. Does the >same when booted from the Tiger DVD. > >Otherwise it runs perfectly. I'd suspect the power supply, or a cold solder joint on one of the circuit boards. If it is the latter, you might notice the problem happening somewhat consistently based on what temperature your computer is at. Randy B. Singer Co-Author of: The Macintosh Bible (4th, 5th and 6th editions) Routine OS X Maintenance and Generic Troubleshooting http://www.macattorney.com/ts.html