I found and read a thread from June 2006 about a 15 inch LCD iMac G4's power supply that died ("iMac G4 Dead Power Supply"). I determined this to be the problem with my 700 MHz iMac also, and used the guidance in the thread along with the service manual to replace the power supply, replace the PRAM battery, reset the PMU and reassemble the unit (with thermal paste, of course)...the unit worked beautifully, but I found that it got hot within an hour or so and it turns out the fan wasn't spinning. I replaced the fan, reassembled the unit (with thermal paste, of course), and viola...nothing.
The fan doesn't spin, but the unit works fine as long as we put it to sleep every so often so that it doesn't overheat (not an ideal situation for a work unit). I can't find any problem with connections, etc., so I'm wondering if I'm missing something.
Any suggestions out there?
Any and all help is appreciated