Hello RBS___
Can you please check and confirm if your PC is connected to two video outputs? Disconnecting the external one might resolve the issue.
If there is only one display output, you can connect your PC to a secondary one (probably to a TV with HDMI), and if the display comes up on the second output, make your main monitor primary.
Connecting your monitor to the integrated graphics card or vice-versa might do the trick too.
Please report back if any further assistance is needed.
Cheers!!