Hi.
It seems I just experienced the same thing yesterday. I’ve had (and loved) my FP3 since approx. May 2020. One moment I was using the phone normally. The next, I put it in my pocket, picked up the kid, and my watch said “bluetooth disconnected”. I took the phone back out and it’s dead: black screen, no reaction to buttons whatsoever.
I tried reinserting the battery without effect.
I connected it to the car charger, not even the LED lit up.
I took out the battery for a few hours, then connected it to the charger a few more, no change.
I tried taking out SIM Cards and Micro SD, no change.
Did you manage to resolve your issue? What caused it?
Thanks a ton, and greetings from Berlin,
Karsten