I had an issue years ago with a tv and a dvd player. For whatever reason, whenever the dvd player was connected, the tv would blank out every few seconds. At some point I posted on the tv manufacturer forums. I did eventually figured out that I leave a thumb drive connected to the tv, the problem disappeared. I wanted to let people know about my work around. I got 1 result – the forum post I had made quite a while back.

I’m pretty sure it was an HDCP issue.