Hi I have a p317-54-70r5, I had actually sent this in to support for this issue, they returned it sayng the battery was not fully plugged in. Come to this morning, it was doing it again. I tried holding the power button for over a minute multiple times. Finaly I just decided to look myself sice my warranty is up. I open up the case removing all the screws carefully using a flat head screwdriver to pop up the case carefully. Got inside no obvious anything disonnected or loose, but still no dice. Finally I decided to disconnect the battery since no battery reset to be found. I plugged back in power, opened case pressed power button wahla woks. Powered off, plugged back in battery connector wahla works just fine on AC or battery now.
WHY DID YOU REMOVE THE BATTERY RESET PINHOLE!!! It would have saved me 4 hours (the fix only took 20 mins to open, fix and close) and a fight with my wife about my time, thanks earnestly Acer. Maybe reconsider getting a "REAL" power button too, so we dont have to question whether it is a defective keyboard as part of troubleshooting.
(Thread was edited to add model name to the title)