Mine still ok...

i experienced this issue lately.
using phone, then the phone would suddenly goes black screen, sometime when double tap it will show lockscreen for around 1 sec then goes black
when this happens, i need hold the power button more than 10 sec to force restart.
sometimes my phone would also randomly restarts, still trying to find the source of the issue.

I have perform hard reset (using about --> reset), now i'm thinking of flashing the phone using computer.
else i might consider sending back for warranty.

any of you guys solved your issue?

Hey kayk,

I sent it to Microsoft 2 weeks ago. They checked, and found out the motherboard got problem. Fortunately still under warranty. Prob is, up until now the spare mb has not arrived, so i'm still stuck with my backup phone (a 1020, which has a dying battery as well).

If resetting to factory does not solve the prob, it might be the hardware.