Tablet [Q] device keeps shutting down

ok have I missed something? I have root and my kindle hd 7 is on 7.4.6 and it just keeps rebooting at random it never did this on 7.4.3
I belive it updated by itself to 7.4.6 I do have gapps and google play installed. is there a fix?

not to sure about trying to set up a dual boot maybe I will have to do some research on that option.
thanks in advance