My phone has been scarily black-screening and getting locked up, resisting all blandishments, threats, refusing to respond to the on/off button....
Removing the battery brought it briefly back to life yesterday, but this evening, once again, it refused to communicate with me. Eventually, reluctantly, the screen came back, and slowly responded.
Perhaps there are a few outstanding updates?
Well, yes. Thirty. So many that we plugged it into mains power to make sure it didn't run out of battery.
Fingers crossed that this will solve the problem.