Macbook - Only turns on when power button is held down.

[Jayce]

Has anybody ever seen this? I'm trying to fix this Macbook (2009 or so I believe) and it's just not making much sense to me. If I press the power button like normal, it begins to turn off but seconds later shuts off. I took it apart and checked the connections, all is well and all circuits are clean. I replaced the top case (which controls the keyboard and power button as well) with a spare I had on the shelf... same deal.

On accident I pressed the power button and didn't realize I was still holding it in. Surprisingly, it turned on. When I began to try and replicate my steps I realized holding it down for 20+ seconds resulted in it turning on and staying turned on. Once it's up and running, it runs great with zero issues whatsoever.

Any suggestions in regard to what you may think it is?

 

[35g700]

Did you reset the SMC?

Intel-based Macs: Resetting the System Management Controller (SMC)

 

[Jayce]

Yup. Been there.

 

[S0ULphIRE]

Hmmm, interesting one. Never seen anything like that, my boss might've though. I'll ask him when he gets into work

Tried resetting the PRAM? If it quits out before you can do that, open it up and remove *one* stick of ram, then boot and try resetting again.

 

[Jayce]

Hmmm, interesting one. Never seen anything like that, my boss might've though. I'll ask him when he gets into work

Tried resetting the PRAM? If it quits out before you can do that, open it up and remove *one* stick of ram, then boot and try resetting again.

I tried to do that, but I had trouble doing so as I need to hold the power button to fire the system up. That key combination (power button + regular PRAM reset buttons) yields no dice.

 

[S0ULphIRE]

Try the one-ram-stick thing? No idea if that'll work for this problem, it's the only thing I can think of that's ever influenced a situation like this though. No high hopes :*(