Smartphone HUM

"A lot of money to fry over a ground loop.."

Indeed. Perhaps consider less power consuming gear running off the grid is warranted. Do you really need to see a projected video image from a system designed to run off the grid?

Though you found a work around for the problem, look at how much of that DC supply power is being wasted through conversion back and forth. If measured and compared, your probably using up just as much wattage or even wasting as much as if you were hooked into the grid.

Sometimes when living off the grid, you have to sacrifice a few things to maximize the benefit of living off that grid! 🙂

RFB

I'm with ya but I do enjoy a little luxury. I watched a 9" screen for years.. 🙂