Currently Being ModeratedJul 12, 2011 7:15 PM (in response to Mac OS 9000)
Dust can cause the problem. If the heat problem went away, you've taken care of it. If it is still there, maxing out the fans is the wrong way to go unless there is something wrong with the fans. The fans are set so that the air velocity is sufficient to keep the computer from overheating. No adjustment of the fans RPM is necessary. Adjusting it is only a temporary solution to a more serious problem that needs a technician's help. I believe the Intel iMacs when they first came out had problems with the screen but I don't remember anything involving the fans.
Currently Being ModeratedJul 13, 2011 12:13 AM (in response to Edward Boghosian)
The problem persists, although cleaning it out seems to have helped. I took it apart after it crashed 3 times in a row, and I got really upset and took it apart for cleaning. It doesn't crash as much anymore.
I am 100% sure that the fan revving helps, but I can only do it while I'm playing a game or something. Constantly firing the fans is bad for the computer...
I've heard that a failing graphics card can overheat really easily, so I probably have a failing card. Keeping the iMac cool helps a lot. We're working on fixing the air conditioning in my room so it doesn't get too hot.