If you want to check your heat monitors (one could be going bad), get the FREE app, iStat, here at: http://www.versiontracker.com/dyn/morein...

My 17" G4 kept shutting down unexpectedly and when I used iStat, I saw the "heat" on one of the (5) heat monitors shoot up to some absurdly high heat just before the laptop shut down (actually, it seems it was doing a sleep, but whatever -- screen went dark.)

Try iStat, keep an eye on it for a bit and see if one of your heat monitors is erratic. When I found which monitor had failed, I googled instructions on how to fix it myself (just removed it entirely) and the 17" is working great now.

[quote|emil]If you want to check your heat monitors (one could be going bad), get the FREE app, iStat, here at: http://www.versiontracker.com/dyn/moreinfo/macosx/27037 My 17" G4 kept shutting down unexpectedly and when I used iStat, I saw the "heat" on one of the (5) heat monitors shoot up to some absurdly high heat just before the laptop shut down (actually, it seems it was doing a sleep, but whatever -- screen went dark.) Try iStat, keep an eye on it for a bit and see if one of your heat monitors is erratic. When I found which monitor had failed, I googled instructions on how to fix it myself (just removed it entirely) and the 17" is working great now.[/quote]