[SOLVED] Random No Signal at the monitor

[mk17th]

hi everyone. recently I bought SSD m2 and installed it, updated my motherboard BIOS just in case and reinstalled Windows. the first issue that I faced pc does not wake from the sleep mode, so I turned it off. some time after it started to lose signal from a graphic card randomly, mostly during gameplay and after closing the game (to be accurate R6 Siege) when display switches between resolutions when display blinks. Signal Desn't appear even after restarting computer.The only thing that helped me when it happens was to unplug and plug back the videocard. Also I've had random stutters when pc slows down and sound starts to glitch for about half a minuteI think it might be PSU (it was making fan noise, but recently stopped, shw)its old,but I afraid it is dying motherboard problem(maybe I damaged it when I was installing SSD smh),and even worse, graphic card. I don't even know what to think. And sorry for my poor english)

What I tried:
changed to default overclock settings on both cpu and videocard - no changes,now,pc works on stock
switched ssd to another m2 plug
memtest86 - no errors
flashed back the motherboard BIOS from 5204 to 4008
cpu temp is about 70 in load (now without OC should be less)
gpu temp is 65 in load

Specs:
Asus Prime x470 Pro
Ryzen 2700x
G.SKill Ripjaws 8gb (2x) 3200
Gainward GTX 1080
Corsair VS650
Western Digital 256 M2 SSD
HDD Seagate 1TB

Update: Today I brought myold 19' monitor and when I pluged it in via hdmi and turned on my computer signal appeared,in the same time my newer monitor don't have signal

 

[mk17th]

that was Display Port cable problem. I switched to HDMI