iMac 2019 4k No Power - 820-01237-a

spackidagoosh

New member
I am working on a clients iMac that will not boot. They state the computer rebooted on its own and then got stuck at the loading progress bar. They do not believe it was some type of firmware upgrade progress bar. After rebooting there is nothing on the display, no chime, and no caps lock. Pram and SMC have been reset. After removing the screen Diagnostic LEDs 1 and two are solid. No others LEDs are active and the fans do spin. The thermal camera is showing two hot spots. One is an Intel Thunderbolt chip on the front of the board and one is a larger chip on the back of the board. See attached. I checked caps around the chips and do not detect any shorts.
 

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2informaticos

Administrator
Staff member
May need to test known good BIOS, clean ME.
Don't forget to make backup first.

820-00597 schematic may help you.
 
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