So 2 weeks after building my computer, it was working fine but then one day I turn it on and the fans are spinning abnormally loud so I restart my computer but when it tries to turn back on it doesn't display anything on my monitor.
So for about 2 hours I am try to fix the problem then it randomly fixes it's self when I was turning my PC on and off.
But now 3 weeks pass and the same thing happens. The computer was working fine in the morning. Then I need to leave the house. I shut down my computer and leave for the whole day when I come back in the evening and turn it on, the fans spun abnormally loud again so I knew what will happen if I restart my computer so I just leave it hoping it will stop but then after a while I noticed that the contrast in my main monitor went down. So me being scared by this, I restarted my computer. And again the computer didn't want to display anything. There is no problem in the monitors as I connected them to my PS3 and they worked fine I tried connecting my PC to my TV and it didn't work.
I restarted my computer an bunch of times removing it from the plug and everything. But it still doesn't work. The last time it just randomly started working after restarting my PC a few times.
I having been doings so for much longer than last time and there are still no results. I left it unplugged overnight and it still didn't work. I have no idea what I can do now. I have 2 monitors. The HDMI output port is not broken as I have also tried connecting it with VGA and DVI.
My graphics card is an Geforce 970 GTX.
Also when I plug in my Main monitor to the mother board's HDMI output it still doesn't work my GPU is definitely powered as it lights up and my mouse and key board also light up.

Thanks For reading this far I would be grateful if you help me