Display port randomly(?) disconnects

[JamesH0105]

Hey guys! this is my first post on the LTT forums and I hope I have done it right, I couldnt seem to find the answer so hopefully you can help. 

 

Recently I built my first pc and it all went well apart from a broken motherboard but that was sorted out quickly when I had a replacement. The pc seemed fine with games, web browsing, work and videos all working great, until last week. The pc kept randomly restarting and saying "display port disconnected". I think it happens more often when I play games, but not 100% sure about that. I tried changing to hdmi but the same happened, with the message popping up again and the pc restarts. This is especially annoying when playing games because i lose progress I have made and it interrupts netflix and youtube occasionally. 

I tried to reinstall the graphics drivers and I followed a tutorial on a DDU? I think i did that right but after half an hour of gta V, the computer restarts because the display port was disconnected.

I dont have another monitor or tv to test it on so thats unfortunately not available.

Does anyone know what I should do to try and fix this?