Question GPU or onboard graphics help please?

[officefo]

Hi, I had to disconnect my ultrawide monitor from my pc to take it for service. I then connected a basic 24inch 1080P to GPU vis HDMI but 'no signal' then I connected to the motherboard graphics and it worked fine. Then it stopped working after reboot and would only work through GPU again. Now that stopped again. Any idea how to test what the heck is going on? Thanks a lot

 

[Prad_Bitt]

Driver issues maybe