Question Pc won’t come on after being shut down for a while

May 21, 2020
Pc specs
I7-7700 non k
Asrock- h270 performance MB (new)
Samsung evo 860 ssd (new)
Msi 1660 ti gpu
Thermal take 700w smart psu (new)
Corsair vengeance ddr4 2666 ram ( new)
Nzxt 510 case new

Ok so a while back I shut my pc down for the night went to work came home I tried to turn the pc on nothing so I started getting new parts (everything but a power supply ) finally got her all working again and about 2-3 weeks later same thing happened came home no power nothing if I unplug it for a few and plug it back in the MB leds would light up for a second then die. This made me think the psu was bad. So I went out last night bought a new psu came home installed it and to my surprise the same problem.

At this point I don’t have a clue so I completely disassembled the system and put it back together, then bingo everything worked I played on it for about 5 hrs shut it down and back on a few times waiting a good amount of time in between everything worked as it should thank god I have it fixed I goto to be happy, well I woke up to the same problem I have no clue what could be the issue.. if anyone has any ideas the help would be greatly appreciated