ok this is one idea i had remove all hardrive cables from the motherboard and then turn it on see if its a os issue if it doesnt turn off or is acting more normal turn it off manually turn it on again and get into that bios. if this fails try the other ideas below
try taking the coin battery out of the motherboard and placing it back in ( after 5 minutes)
or use the cmos jumper on the motherboard.
( this could also be a issue ive had dead batterys in the past in these boards that caused the bios to constantly reset.)
another idea is getting a canned air duster can
https://www.amazon.co.uk/Star-HFC-A...ords=canned+air+duster&qid=1572482076&sr=8-13
and using it while the computer is turned off and unplugged hold the power down to discharge the motherboard this will drain the caps
then take out the ram and blast it in short bursts into the ram slots see if theres any dust build up in there. if the case is dusty clean it with canned air preferably outside as if its really dirty its gonna get messy lol.
do the same to the power supply fan area basicly dislodge as much dust as you can
do not use cloths or anything damp in the case hence why the duster cans
then reseat your ram and fire it back on its possible when you were moving etc that the ram became slightly unseated and allowed dust into the ram slots.
also just make sure every cable to the harddrives etc is seated properly if your unsure unplug and reseat.
if all this fails id go with a new power supply.
or motherboard.
it could be either of these. i doubt it will be the cpu
the reason i say its either one of these as it seems more of a power issue now
its either the vrms have gone bad on the board
or the power supply has a burst cap and when it draws more power and that caps broken it will just shut off