Chosen Solution
I still have not managed to figure out exactly how the computer is behaving but it seems that whenever I turn it on (being it connected to the power supply or the internal battery) it will remain on without any problem until it is turned off. Afterwards, it will require around 30 minutes completely off (with the battery connected to the motherboard, tho) to turn back on. During this time window, the following symptoms can be observed if the power button is pressed:
- The screen remains black
- No chime
- The fan starts to spin and immediately stops
- The sleeping light is turned on and immediately turned off
- If the power supply is connected, this will keep happening periodically (as if I keep pressing the power button). I still wasn’t able to notice if this also happens when connected to battery-only. I have already tested it with all possible combinations of ram chips in both slots, no hard drive, no peripherals at all, no DVD unit and SMC reset all with no success. I have tried to turn it on without the battery connected to the motherboard but it doesn’t seem to work at all, even after 30 minutes (plus the battery meter LEDs blink 5 times if I press the button to their side, but that’s to be expected as there is no battery, right?). What should I do? Any troubleshooting hints (even if it involves measuring voltages across the board)?
Was this laptop behaving correctly when it was in your possession, or was it like this when you got it? If it worked at one point, was there a particular event after which the behavior started? I would remove the battery entirely – when troubleshooting, it’s necessary to eliminate extraneous components, and since it works on battery power, we know it’s not the battery. My gut tells me it’s a board issue, but as someone who doesn’t repair boards, here’s what I would do: Verify you get the same behavior with another charger. If this was a 15" machine, I’d verify you have an 85W charger (15" won’t power on with 60W), but this is a 13" machine, so that shouldn’t be the problem. Once the charger is ruled out, I’d take out the board, eliminate any dust and corrosion you find, and then I would disconnect the DC-in, let the DC-in and board sit separately and disconnected from power for a few hours, and then put the machine back together. Sometimes a DC-in will acquire what I think of as a “bad charge”, and disconnecting it and letting it sit allows it to dissipate. Also, make sure the DC-in is aligned correctly. I do this by connecting it to power while its screws are out, and putting the screws in at that point so that you can verify the connector is straight as you tighten them. Also, check for metal fragments/staples in the DC-in. I’d actually probably do that before any of this, now that I’m thinking about it….