Apple MacBook Pro / A2141 /No Boot / No Display Output / 20v 2.7a /

[zeydullak]

Hello,

We have a Apple MacBook Pro model A2141 that does not boot and has no display, the fans spin for a few seconds before stopping. We connected an external display and it lit up for a second before turning off, this loop continues indefinitely. There is no water damage and the boards condition look good, we switched it to another donor enclosure but the same problem persisted.

What could be causing this issue?

Regards,
Zeydulla.

 

[2informaticos]

Did you test in safe mode?

 

[zeydullak]

We can't get it to enter anything including safe mode, It does not show any display output apart from a quick flash on the external display.

 

[2informaticos]

Try to access DFU mode, using external switch method.

DFU Mode Restore (Macs) - LogiWiki

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[zeydullak]

Once we get access to DFU mode what would be our next step?
Why are we trying to get into DFU mode?

 

[2informaticos]

If you can complete DFU revive, there may be a chance to save data, if needed.

 

[zeydullak]

In your opinion why the board does not give anything to screen? but port charges uses amps.

 

[2informaticos]

Still looping if LCD is disconnected?

Test the board alone on the desk.
Check diode mode to ground on all big coils.
Compare readings with good board.

 

[zeydullak]

The client mention that this problem started to happen after the board over heated. Do you think reflowing the cpu/gpu could solve this issue?

 

[2informaticos]

You should do any other check possible before reflowing the chips.

If you suspect GPU chip, you can lift (one side) all LA710-40 coils.
In case if Intel side is OK, board should stay on, getting even USB activity.