Model A1224 / Mid 2007 and Early 2008 / 2, 2.4, or 2.66 GHz Core 2 Duo processor

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Dead, Power supply OK, no LED1. What's wrong?


I have an iMac that is dead after a thunder. Now the power supply seems ok, measures 12V and 2V on it, and I ordered another one, as Led #1 do not light up at all. This situation is not described in LED diagnostic order sequence (unless it is the power supply to logic board cable, which I sincerely doubt).

Power supply is singing quietly, other than that there is no reaction to power or power switch.

any ideas? Is there anywhere in logic board I can follow the 12V or the 2V to understand why LED1 is not on?


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I would proceed with getting a new PSU. Most of the times, when the voltage spikes without a surge protector between the outlet and the iMac the power supply is fried. You said it was singing quietly, which normally means that there is a voltage leakage somewhere on the board. If that is not the case, it may have been strong enough to get through to the logic board and cause damage there, but in most cases that is unlikely. Try the new PSU, and if that doesn't work, then it is most likely a dead logic board, in which case, it may be cheaper to get a new iMac, rather than replacing most of this one, and instead selling it as parts to someone who works with these types of computers. Hopefully the new PSU will work!

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Yes, I did get a new PSU, as the knowledge DB said it was the PSU if LED1 was dark, but omitted the logic board solution.

I see I didn't mention that it was connected through a surge protector. As the PSU seems OK, I think perhaps the spikes came in through the internet, while then again, the internet box was not affected. BTW, the PSU singing is almost not perceivable when the screen is connected.

Yes again, I agree it is probably beyond repair, and I will try to swap/sell it locally (DK).



I getting the same problem. MY 2nd PSU is working, because it actually able to power on while I keep trying that day, now no more, while hit the power, the led1 just lit and off (0.5sec). nothing.

Is it logic board problem?


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Kristoffer Jensen will be eternally grateful.
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