[btwom]

Anyone run into this problem? The fan on my PPC G5 (17in) is running whenever the computer is on (or shortly after it starts up). Even if there are no applications open or meaningful processes running.

The panel around the Apple logo (below the screen) is mildly warm but no more than you would expect. Haven't opened the computer to look inside but doubt that the vents (in the bottom) are blocked.

Any ideas about why or how to fix?

[P]

Most likely the fan vents are full of dust - you may not see it, and it's the first thing I'd try. Turn off the computer and go over all the vents with a vacuum cleaner. If you're comfortable, you can remove the back to clean it more fully. If that's not it, try resetting the PMU.

[btwom]

Thanks Elite. I'll try cleaning the vents this weekend. Don't want to sound too stupid, but what is the PMU and how is it reset?

[P]

PMU=Power Management Unit. Controls power usage, cooling, charging batteries etc. It's actually only called a PMU on laptops (minor memory lapse there) - it's an SMU on iMacs, but it does more less the same thing. Apple has a technote on how to reset it.

[btwom]

Thanks P. Things are much quieter around here now.

[peterthorn]

A good tip (even though you have fixet it), is to move the ram around (take one out, boot up and put it back in, or switch them around). That usually also takes care of that issue.

Peter