Skip to main content

Model A1311 / Mid 2011 / 2.5 & 2.7 GHz Core i5 or 2.8 GHz Core i7 Processor

425 Questions View all

Power supply works when logic board is disconnected.

iMac is dead.
I tested the power supply separately from the logic board and all the pins match the expected amounts. When I attach it to the logic board, all the pins are dead, zero volts everywhere.

Q: Does this mean there’s a short on the logic board? Wouldn’t the pins still show a voltage since the short is drawing power?

Q: Do I need to supply voltage to the board to find the short?

Answer this question I have this problem too

Is this a good question?

Score 0
Add a comment

1 Answer

Yes, you have a short within the logic board, often it’s the MXM GPU board that fails.

Time to pullout the DVM and check the power rails for a short (without the power supply connected). You’ll need the board-views and schematics for the system.

Was this answer helpful?

Score 0


DVM? Digital voltmeter, right? (Just checking) ;)


Also, can I assume that the power supply is prob OK?


@Paul Spinelli - Likely, you really need to test the logic board power rails for a short


Add a comment

Add your answer

Paul Spinelli will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 29