820-01521 - restarts at the Apple logo

[Palhano]

It turns on, the Apple logo appears, it starts loading the system and then restarts.

The only thing I noticed is that the MOSFET (Q3200 or Q3100) connected to the port where I plug in the charger is frying. I replaced both and the problem persists.

Any suggestions?

 

[2informaticos]

Did you test with known good battery, holding some charge?
Still restarts with battery alone?
Can you force it in Recovery mode?

 

[Palhano]

I tested it with another charged battery, same problem. It starts loading the system and then restarts.

I put it in DFU mode and restored it, it worked. In recovery mode, it stayed on while downloading, but when the screen to choose the language appeared, it restarted. It then restarted recovery mode again.

 

[Palhano]

I restarted the recovery process and magically it started working. I finished installing macOS and it's stable.

Is it normal for the Q3200 or Q3100 to overheat so much? Does alcohol evaporate?

 

[2informaticos]

Not sure exact thermal behavior for Q3100/200; compare with other working board.