PC not displaying on monitor

I've tried everything and I'm losing hope. So I'm trying to trouble shoot my pc as it was not booting BUT I've taken out the graphics card and ram to see if it was the motherboard the motherboard responded with a beeping. I stuck the ram back in and it eventually booted up saying stop code bad system config I tried to reinstall windows and that didn't work. No idea what happened but now it wont display anything on my monitor again. Any ideas would be appreciated. Thanks.