PC shutting down and restart auto

Hello Everyone please any help ?
so I had a issue where my pc refused to start when pressing power button it just start when it feels like at first I tought it was my psu coolerM 750 v1 gold paired with a gtx1080 and a i5-10600kf who died on me
well turned out to be my motherboard after getting a asrock b460m steelLegend pc does turn on normal ... but now after two days my pc turns off when stressing the cpu or the gpu by aida64 extreme for like 3min only or by inserting any usb device even a keyboard makes it pc shuts off then restart alone after 1-4sec any idea ??
tried bios reset bad connected cable ram memory test nothing and
heat was normal both max 64c so did the psu really give up ??
 
@Kshipper yeah I was thinking so because motherboard rgb lights when I plug power cable are on but psu doesnt want to start only after a few tries
now when it just boot to windows turn off for a sec then restart