I’d start looking at power/connection issues.
Did he bring his monitor and all cables to your place
Do the wall oulets/surge strip outlets that he plugs into work?
Bent or missing pins in vga connector
That sort of thing. It doesn’t seem likely that anything internal is changing between your place and his
Did he bring his monitor and all cables to your place
Do the wall oulets/surge strip outlets that he plugs into work?
Bent or missing pins in vga connector
That sort of thing. It doesn’t seem likely that anything internal is changing between your place and his
