Shut down when transitioning to battery, but will restart with battery
After a liquid spill, the computer was working normally again, except that when I unplug the power adapter, the machine shut down. After this automatic shut down, it only starts up again with the ac adapter.
So I bought a new battery.
However, when trying to change the battery, I manually shut down the machine and unplugged the AC. - Then something very strange happened: the machine booted (and ran). -- So the old battery was still ok.
I still changed the battery. Same problem. Runs with AC, but force shut downs when AC is unplugged. -- When shut down manually, can restart and run on battery.
I have done about 10 SMC resets.
Okay, since people seem to be confused, again the question:
Which components are responsible for the transition from AC to battery?
DC in board, logic-board, NVRAM/PRAM? Something else? Someone with engineering background should be able to answer this.
NB: Please spare me answers like "you need to clean" / "Isopropanol works" / "you need to look under the hood" etc. I know all that. This is not helpful.
Is this a good question?