Pc Turns on but no signal to monitor mouse or keyboard

First, check your connections, and make sure your display is powered on and connected to a power source and to the computer itself. If your monitor still does not work, try connecting the computer to another display. For an HDMI-capable device, If you don't have a spare monitor you should be able to connect to another display that utilizes an HDMI port using the HDMI cable.

For example, you could connect your PC to a High Definition television screen and utilize it as a substitute monitor. You should then be able to use your keyboard and mouse.

If this works you can deduce that the trouble is with the computer monitor and not with the computer itself.