I am not 100% sure what you try to explain but as for the check cable, it might be related to the cable that comes from ur display to the video adapter, check if it's properly connected, or try different display.
Try going into your BIOS, disable shadowing
- If it doesn't work, do try to set BIOS to its default.
- While in BIOS press F9 ( Depends by bios) and it should set it to default then exit.