Htc 8 X restarts itself

First... HTC knows about the problem. Nokia knows about the problem.
Second... if your phone reboots, have it exchanged!
Why, because it could also be faulty memory.
 
I have the same problem. Bought the phone in December 2012 immediately after it came out. Never had any problems until a few weeks ago. Phone reboots randomly without notice. Today alone 6 times. Had this phone for 18 months without a problem.
A few weeks back, right before the rebooting issues started, the phone drained once in less 3 hours. From fully charged to zero battery without using it. I have the impression that the problems started after that "event". Maybe related?
 
I have the same problem. Bought the phone in December 2012 immediately after it came out. Never had any problems until a few weeks ago. Phone reboots randomly without notice. Today alone 6 times. Had this phone for 18 months without a problem.
A few weeks back, right before the rebooting issues started, the phone drained once in less 3 hours. From fully charged to zero battery without using it. I have the impression that the problems started after that "event". Maybe related?

On Verizon? There was an update to the HTC8x from Verizon pushed on 7/08/14. A few people have had some issues (still to be firmly determined if linked to update) that affected mostly WiFi (became glitchy). However one user reported restarting issues (again, may or maynot be related to update). See this wpcentral thread in the HTC8x forum.

In any event another poster said that swapping out their SIM card at the Verizon store solved the restarting problem.

Maybe give that a try.