I'm using ASRock n69c-s along with NVIDA GeForce GTS 450 (old I know) and today when I came back from logging out from my PC for 2 hours I noticed the resolution had lowered.. Logged in and tried to up the resolution again and there were no higher options. Confused, I restarted my PC only for it to not start, I got 'no signal' come up and there was 1 beep every 30 seconds or so coming from the computer. Tested the monitor, the cables, and graphics card on another PC and they all work fine. The Pc loads up if I start it without the monitor cable in, I plug it back in and try to install the drivers for the graphics card and it just shuts off again.

This is completely random, happened while I was AFK, I'm a hardware noob so I don't know if that's all the info needed.

Anyone know the issue or have a suggestion?

Thank you.