Phone is Oneplus One running Cyanogenmod (usure about the version but it should be the latest released to OpOs)
It all started after a metal detector scan - the phone would work for 20-30 seconds fine and then the screen would freeze indefinitely. Upon restart you could see the same behaviour. Once I was back home I plugged it to my laptop to try to retrieve some of the data and noticed that while connected the phone was absolutely fine.
This led me to believe the issue is software related so I did a factory reset. Unfortunately, after that the issue remained so I decided to try to flash the ROM. Started by turning off my phone so I can go into the fastboot menu but now after turning it off it won't turn back on.
I'm certain that it isn't a battery issue but I'm running out of options. Neither power + vol up or power + vol down work at the moment and connecting it to the laptop does nothing.
Any suggestions what to do next?