MacBook A2141 one USB port dead and one power cycling

[mon2]

A number of parts are linked to this power rail including the cap cluster @ L7813. Would you have an adjustable power supply? Dial it up to 1V and as high current as supported by the power supply and use it to inject @ L7813 (with no power to the board). The shorted part should heat up and be visible.

[dbuergi]

That's U7800 lighting up. T2 chip only gets some heat. So remove it and check if there is any change?

[mon2]

Personally cringe at the PMU ball size for rework. Flux and carefully lift up L7813. Then measure the resistance to ground again.

Which side is shorted? U7800 (PMU / producer) or downstream (consumer) side?

[dbuergi]

Short is at the downstream side.

[mon2]

Good. So U7800 is safe.

Inject again and review who heats up. Hope it is a cap.

[dbuergi]

Good. So U7800 is safe.

Inject again and review who heats up. Hope it is a cap.

Sadly it's no cap...only T2 is heating up at 38C with 1V and 5A injection... So it's over and i have another donor board?