Please help me pc problem

[GAKATTACK40]

Hello community ease help me! My computer turns on the graphics card fan is running and the lights in my pc is on but nothing is shown on my monitor and my keyboard and mouse won't work. I didn't touch the pc and has been working fine after I built it. Please help me!

 

[Coruonel]

First check to make sure the power cable is plugged into your monitor.
Next check to make sure the cable between your monitor and your PC is FULLY connected, making sure it's connected to the Graphics card, not the motherboard's video outputs.
If that didn't solve the problem, disconnect the cable from the graphics card and connect it to the motherboard's video output. If this solves the problem, go into the BIOS (hit delete or F1/F2, whatever your system asks you to press at startup) and change the default video adapter to either "Auto" or PCIE. At this point, shut it down, and swap the cable back to the Graphics card. Let me know if this fixes it or if you need further troubleshooting.