Hi all. Can someone help me troubleshoot a problem with an iMac I recently obtained from a fellow ehmac'er thinking (foolishly) that I would probably be able to fix it myself?
When cold, the iMac boots and runs normally.
I have no hard drive installed so I am just booting off the MacTestPro CD for this machine.
Once the iMac warms up (approx. 20-30 minutes), the screen will power off (you can hear it power down) and the power light on the front will start to pulse a dim green. You can also hear a slight clicking as the power button brightens and my optical mouse flashes on at the same time as the power button pulsing.
So far I have tried reseating the RAM, changing the battery, and resetting the PMU. When running the MacTestPro tests I do not see any failures although the test never gets a chance to complete before the iMac warms up and shuts down.
Once this happens, I need to let the iMac completely cool down before I can start it up again. Then the cycle starts all over again. If I unplug the iMac and wait 10 seconds then try starting again, the green light comes on but the iMac does not make any sounds like it is attempting to power up.
As this is a heat related problem I am thinking that there may be a logic board problem or a bad solder joint somewhere that only affects the unit when it warms up. My only problem is I do not know the first place to look to try to eliminate this and given the cost of replacement parts, I can't afford to start buying and swapping parts to see if the problem goes away.
Any advice will be greatly appreciated.
Larry
When cold, the iMac boots and runs normally.
I have no hard drive installed so I am just booting off the MacTestPro CD for this machine.
Once the iMac warms up (approx. 20-30 minutes), the screen will power off (you can hear it power down) and the power light on the front will start to pulse a dim green. You can also hear a slight clicking as the power button brightens and my optical mouse flashes on at the same time as the power button pulsing.
So far I have tried reseating the RAM, changing the battery, and resetting the PMU. When running the MacTestPro tests I do not see any failures although the test never gets a chance to complete before the iMac warms up and shuts down.
Once this happens, I need to let the iMac completely cool down before I can start it up again. Then the cycle starts all over again. If I unplug the iMac and wait 10 seconds then try starting again, the green light comes on but the iMac does not make any sounds like it is attempting to power up.
As this is a heat related problem I am thinking that there may be a logic board problem or a bad solder joint somewhere that only affects the unit when it warms up. My only problem is I do not know the first place to look to try to eliminate this and given the cost of replacement parts, I can't afford to start buying and swapping parts to see if the problem goes away.
Any advice will be greatly appreciated.
Larry