Liquid-damaged 820-00165 (Air 2017) with updating issues

[sekidata]

I'm trying to revive an old 820-00165 board with liquid damage. I replaced several corroded components around U1950, U5000, U7701, and U6100, including the SMC, backlight driver, and EFI chip. Now this machine is running nicely and passes Apple Hardware Test. But whenever I try to update the OS, the machine restarts to begin updating, then stalls - the fan spins up and stops, spins up and stops, and so on. Only unplugging the battery makes the board start up again (and the update is not applied).

Any idea why the machine works fine except during OS updates?

 

[2informaticos]

Did you replace U6100?

 

[sekidata]

Yes, and I flashed it with a clean ME region file.

 

[sekidata]

I tried various OS updates and noticed that the system possibly hangs during Boot ROM (EFI firmware) updates. What components are required for the logic board to write to U6100?

 

[2informaticos]

Check Q1920 and its related resistors/traces.

You can also update macOS in other machine and put back the SSD.

 

[sekidata]

Couldn't find anything wrong in the Q1920 neighborhood.

Yes, I could update the SSD but the Boot ROM would be stuck on an ancient version from 2017. And no further updates could ever be run.

 

[2informaticos]

Try to flash the SMC, with MuertoGB's tool from github (SMCTool).

 

[sekidata]

Ok, I reflashed the SMC using the 820-00165 file with SMCTool. No change. There must be a hardware issue.

 

[2informaticos]

Change U6110; check the board pads and traces first.

 

[sekidata]

Tried that and no change. I think it's time to call it quits for this board.