I have a Macbook pro with this symptom: it’s not powered on , tried to hold the power button for long time , still nothing happen. I tried with and without power adaptor, result is still the same.
I open the laptop and disconnect the battery, connect the power adapter , it turns on and working perfectly.
Is the battery bad? i connect the battery back, it’s working fine. But then i shut it down, i can’t turn it on back.
what is the issue? it’s because the power key is dead. The power key is a part of keyboard system.
Solution? there are 3
- replace the keyboard: the keyboard is pretty cheap, about $22, but it will require you to disassemble the whole laptop. It’s not easy, but if you have time, follow some youtube videos, it will take about 2 hours to complete this task. I like this video https://www.youtube.com/watch?v=iXJBAlM32NY
- Disconnect the battery completely : there will be some performance issues when the system does not see any battery connected.
- unplug power adapter, Disconnect the battery , wait for few minutes, while battery disconnected, hit many keys to discharge all electrics, this will reset the SMC. Connect the battery back, connect power adapter back, system will turn on. There is a down side with this solution: if you shutdown the machine or battery is dead , you will have to go to this process again. With this solution: never shutdown your laptop, you can put it in sleep.