Re: iMac A1418 21 inch 2013/2014 820-3588-A NO POWER, FIXED!

I have the same board and the same problem, the iMac seems dead.

I had only LED 1 on, LED 2 blinking one time when pressing power button but no power to the board. I was checking voltages on the board and when I was checking U6970 suddenly LED 1 disappeared and voltage from the PS went from 12V to 11.6V (it's still 11.6V now). Also I still have LED 1 off.

Is it possible that when measuring with my DMM a short has been made between pin 1 and pin 2 of U6970 and that PP12V went directly to the SMC...

Re: APPLE iMac (21.5‐inch, Late 2013) 820-3588-A not turning on, faulty PS?



EDIT:

Now I have no LEDs at all, I measure 11.6V at 12V pin on the board and no more PP3V3 or PP3V42. Is still a PS fault o do I killed the logic board? LED #1 went off when I was measuring U6970, I measured PP12V on pin 1, SMC_PM_G2_EN (3.4V) on pin 2 and then poof, no leds. Maybe a short between PP12V and SMC_PM caused by the DMM?...

Ciao a tutti! I was given an old late 2013 iMac that doesn't turn on. I have the .brd file and the schematics and I've done a little analysis on the boards. Starting from the PS it appears to have 11.6V instead of 12V and that is a little strange, isn't it? Measured test points for PP12V_G3H and gives me 11.6V as well.

The iMac have two different types of behaviour:

1) no button pressed when inserting AC cable; inserting AC cable turns LED #1 on, when pressing power button LED #1 turns off for half a second, then turn on again, LED #2 turns on for half a second and...

Re: New Members - please post your introductions here

Hello, I'm Rob, from Italy. EE student and diyer, looking forward to learn how to repair PCs