Galaxy S4 constantly restarting on its own.

[Louis Rafael]

My 15-month-old S4 has recently began to restart on its own at what seems to be random.
The times when I saw it about to happen the wifi shut off (or at least disconnected) and it showed a data network connection just before restarting.
It has happened whilst in normal and safe modes, whilst being moved and not, charging and not, and at what seems to be any amount of battery remaining.

Running 4.4.2

Similar, but not same threads have suggested battery being at fault, but it is restarting and the battery is, as far as I can tell, still flat.

What do you guys think?

 

[Golfdriver97]

Take the battery out and on a flat surface, try to spin it. If it does, it is bulged. If it doesn't you can try rebooting into recovery and clearing the system cache.

 

[Louis Rafael]

Thanks Golfdriver97, I tried both of those things and it's still happening - any ideas?

 

[kaklon275]

Go to Customer service center to have a check for the HW

 

[Louis Rafael]

Think they'll do that for free and not blame my cracked front glass? (digitiser intact)
I plan on replacing the glass, but only if i can get the rest working properly....