Diagnostic led 1 stays on until hard drive plugged in

My mid-2007 iMac 24" 2.4 Ghz stopped working.

It would just shut down after being on for a few minutes, and eventually wouldn't power on at all.

I did some reading (big thanks to all the contributors at iFixit - such a great resource!) and learned about the 4 diagnostic LEDs inside the computer.

I opened up the machine and saw that the first LED was turning off after a while. I removed the hard drive and noticed that the first LED was now staying on all the time. Could the hard drive be drawing too much power or something? I tried another hard drive and had the same thing happen.

If I put the hard drive into a Firewire enclosure, I can boot off of it, and the computer does not shut down.

I'm hoping someone here (Mayer!) can give some advice as to what I might do to repair the iMac.



Update: now, led 1 doesn't stay on for more than a few seconds.

Is there a way to determine if it's a power supply problem or a motherboard problem? I'm willing to replace the power supply but the motherboard is probably more than the computer is worth.

Answered! View the answer I have this problem too

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Sounds to me like a failing power supply. How are your diagnostic lights when booted from your firewire drive? Try booting from your original system installation disk and run Disk Utilities on your firewire hard drive and see if it has issues.

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I agree. My power supply was bad, which in turn took out the logicboard. So get it fixed ASAP.


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