We're trying to identify why a macbook won't boot into any MacOS or Mac related recovery mechanism and what we can do to correct this. The answer we've gotten so far is that it's the logic board, but the device boots into Ubuntu just fine (noted below). We think that if it were the logic board, this wouldn't work either. We're looking for suggestions on troubleshooting steps which would make sense in this context. Details below:
I've been working on troubleshooting a macbook pro which was donated to our makerspace which was rebooting over and over again when plugged in. We did the standard stuff like attempting to boot in safe, recovery, clearing the NVRAM. We tried fresh install from an external USB, all have the same effect, that after you make a selection or it starts the boot process past the apple logo, (i.e. holding option and selecting a boot device, or using recovery and trying to boot to the recovery system), it stops, no error, and then reboots.
I was able to get the machine to boot completely into an OS from an external Ubuntu drive and then had the idea, what if I install Ubuntu on the machine and then overwrite that install with Catalina, to see if that might sidestep some wonky firmware gremlins (granted I'm out of my depth here, which is why I'm asking for help). Ubuntu installed fine and boots up without issue from the internal drive, but when I tried to install Catalina, it started doing the reboot thing (meaning, selecting option on power up, then selecting the Catalina USB install stick, it starts booting from the stick and then reboots).
