If the PC is running fine but nothing is showing on your montior, it means you are having display problems.
Check all the cables running from your monitor to your PC. Are they connected into the right display port? (HDMI, VGA, DVI, DP, etc)
Is your GPU (graphics card) running?
Have you tried using the integrated graphics in your CPU (if it is available)?
Is your monitor on?
Feel free to comment below any questions or concerns
-Lachlan