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Model A1419 / Ende 2013 / 3,2 und 3,4 GHz Core i5 oder 3,5 GHz Core i7 Prozessor, ID iMac14,2

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iMac 27 late 2013 won't power on

My iMac won't power on. I've tried all the simple stuff - power is good, reset SMC, but still no avail. What can I do next? I'm tech savy and have worked on computers my whole life but never has an issue with my macs like this before. Any next steps would be greatly appreciated!

Just to make sure I'm not making a simple mistake - what I'm pointing to on the logic board is the LED's correct?

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Tell us what the LED diagnostics light to the right of the RAM slots are indicating.

LED 1 - Indicates that the trickle voltage from the power supply is detected by the main logic board. This LED will remain ON while the iMac is connected to the AC power. The LED will remain on even when the computer has been shut down or put to sleep. The LED will turn off only if the AC power is disconnected or the power supply is faulty.

LED 2 - Indicates that the main logic board has detected proper power from the power supply when the computer is turned on. This LED will be ON when the computer is turned on and the power supply is working correctly.

LED 3 - Indicates that the computer and the video card are communicating. This LED will be ON when the computer is communicating properly with the video card. If LEDs 1 and 2 are ON and you heard the startup sound, but LED 3 is OFF, then the video card might be installed incorrectly or need replacement.

LED 4 - Indicates that the computer and the LCD display panel are communicating. This LED will be ON when the computer is turned on and video signal is being generated. If the LED is ON and there is no image on the LCD display panel, the LCD display panel or inverter might be installed incorrectly or need replacement.

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Do I have to open the machine to see those lights?


Yes you do. But first please tell us all the symptoms and why you think the power is good. What lights, and sounds are you getting?


Basically I get no power whatsoever. I've tried new outlets, ensured there was power with a lamp plugged in first, new power cable to computer, press and hold the power button for 10 seconds. Everything I've tried results in no charge on the iMac. No power, no lights, no sounds, no fans, no hard drives.


I'd go for the power supply first:

iMac Intel 27" EMC 2639 Netzteil ersetzen


Thanks! That's what make sense to me too - I'll let you know how it goes! Once I get to it is there any guide to determine if it's a good power supply or not?


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Just had the same problem after installing an SSD. Make sure that the power button cable is not severed. Mine was.

Once I took the two button cables and connected them, it turned right on.

In order to fix it, you’ll have to push the physical button out of the back casing.

NOTE - It looks like you have to unscrew the button from the frame (which looks impossible, and is), so don’t try to do that. It is only held in by some pretty strong glue, so take your time, but it will just push and wiggle out.

Once you have it out, there are 3 screws as a guard for the circuit. Take those out and you will have access to the leads, which you will need to re-solder the cables to.

  • Be careful when removing the broken wires from the leads!! ***

I almost tore one of them off very easily, so be patient.

Once done, screw the circuit guard back onto the frame of the button. I superglued the cables to the hole where the frame that it comes out of, but don’t do that if you worry.

Once screwed back together, test it to make sure that you fixed it. If it works, you can wiggle it back into the casing and reassemble the machine.

Stupid mistake, but took me 3 days to consider that as my mistake. This is so you won’t be plagued for as long.

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Resurrecting this. I'm still using a 2013 iMac in 2023. I was experiencing random shutdowns and the computer would not turn back on until it was unplugged. I replaced the power supply, but after sealing back up my mac it started doing it again. I believe in my case, the iMac was overheating. I looked up with a flashlight up into the bottom vents and there was dust visible. I turned off the computer, did a thorough careful vacuum and have been monitoring temperature with Macs Fan Control. So far, no more random shutdowns.

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When you did the power supply replacement did you make sure to remove the fan to clean the fan and the fan blades on both sides for better cooling? I usually use a brush on all client SSD drive upgrade jobs so whenever I open a machine I make sure all dust has been removed from inside, especially around the back of the logic board where the USB ports are as dust over the USB ports on the board can cause moisture build up in the dust and cause the USB ports to short-circuit or damage further the logic board. Also, the front grill can accumulate a lot of dust in the front bottom grill and it's good to use a compressor to clean it out. Just make sure there is no condensation in the compressor air as that can spray onto the logic board and cause issues in the future. Also with random shutdowns, most probably not but Apple Genius staff tell their clients to try a separate self-powered AC port I the wall (not on a powerboard) and try a different power cable to troubleshoot the issue.


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Blasted power button connector!

So, if you find yourself, moving the speaker over to get to the hard drive screws, pay close attention to the small two-wire connection at the top left corner of the PSU board (if facing the Mac). The small wires run discreetly down the speaker and to the left corner. If they’re not connected securely, pressing the power button will do nothing . . . except make you go mad.

Just you and LED #1. Going nowhere fast.

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Luke wird auf ewig dankbar sein.

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