Sounds like a grounding issue. Your power supply does not have the same ground as the TV or the PC to which the USB cable is connected. The way around it is to fix the grounding issue.
Gerald
Yep. Definitely a grounding issue. It appears the hdmi cable does not tie the grounds to the outside connectors. If I hold a wire to the outside metal of the HDMI connector on the BBB and the outside metal on the DVI connector of the monitor it works great. I’ll try soldering a thin piece of wirewrap wire connecting both on the cable and see how that works. I’ll post a picture if it does. Of course buying a better cable would be better, but what fun is that?
You should also be able to use a grounded power supply as well.
Gerald
Probably, but at the moment its just a wall wort.
BTW. Tying the 2 cable ends worked like a charm.
Thin piece of wirewrap wire carefully soldered at the base of the cable on both ends of the cheapo cable.
Happy Camper…
Great! Looks like we are having some grounding issues. Bad cables and maybe bad wall warts with no earth grounds.
Gerald