Troubleshooting a dead unit
Hi there, bought an untested one of these hoping to get it going again. Not sure if these models are supposed to have a charging indicator light, but there is none. No power when started. PMU/PRAM reset does nothing. Have tried to start the machine with the battery, AirPort card, and RAM all disconnected, and with two different AC adapters - machine still shows no signs of life.
Am not an EE and fairly inexperienced with diagnosing power issues. I haven’t opened up the unit to inspect the DC-in board but I have tested the battery pins with the machine plugged in. Each battery pin will read between 0.3-0.6v so there’s clearly power getting through the machine but no fan spin.
I have a few different ideas from here but I’d like to know which one makes the most sense. I don’t think the DC-in board is bad if power is getting to other parts of the machine, but I think I should open the machine up to inspect for blown capacitors or other noticeable damage and check the voltage regardless. I’ve read various materials about the PRAM capacitor dying and preventing the machine from booting. I was also thinking it is possible the power button mechanism could be faulty. These machines should boot entirely off AC power, right? Please let me know if there’s anything I might be overlooking or something I can do to determine the no power fault on this board. Thanks!