Question Monitor would randomly go black and now Pc shuts down randomly

[Ricky285]

I built my pc in November of 2019 and everything was fine and I loved it. Around January my monitor would just randomly go black for a few seconds and then come back on. A few times it wouldn’t turn back on and I would have to turn my monitor off and back on and it would be fine. Just today my pc would just completely turn off and I wouldn’t be able to turn it back on for a few seconds and when I would press the power switch the mobo lights would flicker. I had to disconnect the psu from my surge protector to turn it back on. After a few minutes it turned off again and would have to do the same thing. I ran stress test like heaven bench and cine bench and would be fine for about an hour but then the same thing happened. What also was weird was that when the pc would turn off the monitor and my phone charger connected would also turn off. I’m not sure if that happened the first couple of times. So now I’m not sure if it’s something with my pc or my surge protector. I’m new to computers and don’t know much about them. Sorry about the long read just trying to put in as much detail.
Build
Cpu: Ryzen 7 3700x
Gpu: Zotac gaming 2070 super twin fan
Mobo: Gigabyte x570 arorus elite
Ram: Corsair vengeance lpx 16gb 3600
Cooler: nzxt kraken x62 280mm
Psu: Thermaltake toughpower grand rgb 750w
Storage: 970 evo 500gb m.2 and seagate barracuda 2tb
Case: nzxt h510

 

[Oussebon]

Do you have another surge protector / extension lead to try?