820-01598 half-brain dead

[macfixer]

Have a weird board here,

It came in for "macbook chimes but doesnt start"
Fan spins, trackpad clicks, usb-c ports provide power
No display at all, no external either, tested new display
DFU revive went through, although it didnt end in the lock symbol but DFU symbol, no change
Data is extremely important
Ive tried the "boot" menu by holding power button, nothing happens
No visible damage on board
Just some stains on wifi antenna
Cpu gets warm

I have not yet measured power rails, but im not sure if i would be missing any, as i only seem to not get display

 

[2informaticos]

Test if you can detect its SSD in Target Disk mode.

 

[macfixer]

I have tested target disk mode, but i was under the impression this model used Share Disk mode instead, so additional input needed?

 

[2informaticos]

Can you detect USB activity at any moment?

Holding power button for boot menu works for M1 machines.
Did you test with Alt key?
No need to press power button at all for this.

 

[macfixer]

Tested alt key with a usb stick (with activity led), i get one single blink when i "boot" and hold alt, then its completely inactive. Braindead?

 

[2informaticos]

Looks like board gets stuck immediately after chime.

Did you try DFU revive more times?

 

[macfixer]

Tried revive again, this time i get the lock symbol.
It went through two times.

Tested target mode after this, also pram for 1 minute, nothing happens.
Still no activity LED

 

[2informaticos]

What is the final CPU core voltage?
Test the board alone on the desk, only with USB stick.

 

[macfixer]

Only voltage on inductors i have is 1v on L7270
L7420, L7210, L7220, L7410 are 0v
PPBUS_HS_CPU=12.59v

Board bare on desk, only charger connected, still draws 0.2a

 

[2informaticos]

DFU restore may be the last chance...