Led501 1 Is On But Nothing When The Button Is Pressed Imac Intel 27 Emc 2429

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Hi, I’ve got a A1312 and try to fix the problem : The first led (LED501) is on, means that the power supply is good ? But when I press the button to power up the iMac, nothing is happening, LED502, 503, 504 stay off. I think the problem could be the button or the power supply ? Thanks!

Have you tried jumping the button contacts at the logic board?

It does sound like you have a bad power supply iMac Intel 27" EMC 2309, 2374, 2390 or 2429 Power Supply and here’s the guide iMac Intel 27" EMC 2429 Power Supply Replacement Often a power surge or a lighting strike will kill your power supply. Do make sure you have a good surge suppressor (not a power strip which has no protection), better yet get a good UPS!