How can I stop my Note Pro (SM-P900) from freezing and random rebooting?

[AC Question]

Bought refurbished unit. Problem occurred from day 1. Have done factory reset and boot to safe mode. Still freezes after about 5 min or just reboots.
I know it's probably a hardware issue, but what should I be looking for or telling a repair tech.?

 

[Beut]

Easy fix, just look for the threat Flickering Screen, different problem but causing by the same source: cracked battery connector.