Hi there, thanks for the tutorial!
I have a MacBook that starts up when connected to charger, but then restarts after 3 seconds, and repeats the cycle indefinitely. When disconnecting the battery board data cable it starts on charger cable just fine.

Is this a clear sign that the battery board/battery is faulty, or could it also be that there is an issue with the logic board? I don't want to replace the battery just to find out that there is something wrong with the logic board. That would be sad.

Thank you!