PC keeps turning on and off in either Safe Boot / BIOS

[MercLTP]

I have a PC that the monitor keeps turning on and off, i know thats its not the monitor or the GPU's fault. Also the gpu is quite new, it also only happens in BIOS mode or Safe Boot gets really annoying when I try to fix my computer for other problems

https://youtu.be/KMrD2-v9rX8
Currently in the video I'm just checking for my Ram health via Windows Memory Diag. But simply put it only happens in safe boot/BIOS

 

[Tolis_GR]

Looks like a faulty cable/port or bad connection. Reseat the cable, clean the connections then try another cable or port.