820-01958 20V no CPU Core

[down1nit]

Water damage near Q7660/Q7680 (p5vg3s and 3v3_g3h). Replaced obviously bad ones, lifted the fets/cleaned pads. Every power is present but CPUVCC and screen/backlight as far as I can tell, even lid signals.

Not stuck in DFU, had to force DFU using keycombos to make sure. Just "macintosh" in sys profiler unless i force dfu. Didn't restore bridgeos, customer needs data preferably, assuming possible.

PCH is getting power and warming up ok, what's next to check on this? Thanks!

 

[2informaticos]

You can try DFU revive; it will not erase de SSD.
Restore is the option which does that.

No voltage at all at L7210?
L7400 has correct voltage?

 

[down1nit]

I will try revive. No voltage on any phase, 1.8v on L7400

 

[down1nit]

Tried revive 2x on a brand new 16" w/ monterey. Seems to complete, then i get a reboot and a lock symbol on the bad device's DFU icon.

CPU still no volt

 

[2informaticos]

Be sure to use 96/140W charger with 16".
Better to connect known good battery too.

 

[down1nit]

I'm repairing a MacBook Air. The 16 hosts apple configurator 2, I was trying to revive the Air board using the 16 lol. The battery seems good. Battery LED illuminates and my ammeter reports 2amps being sucked into battery.

 

[2informaticos]

Aaaa, OK; got confused with 16"...

Possibly CPU damaged because of liquid spill.

 

[down1nit]

Yeah I think some got under there. The CPU sorta just asks itself to be enabled when all the conditions are met right?

 

[2informaticos]

CPU core voltage generation is complicated.
Is not just enable signal required, like for other secondary power supplies.