Facing TV Problems? Ask a TV Technician.
Did you touch any other settings beside the Factory Reset?
You actually need to START HERE --
type 46A1UF0E. Yes that would be the one you use.
As for the HDMI issue, that android could have caused >>a specific<< HDMI to only respond to the android causing it to only allow the android to function, and ignore all others. I have seen that happen on some HDMI inputs. The other equipment should still function on the other HDMI inputs. That's what I have seen. If you test it this way, do you find the other HDMI ports usable, or did the android cause the other HDMI inputs to stop responding to your other devices?
So you replaced the main board and the same thing happened to that one??
I've seen entire HDMI inputs fail one at a time..The HDMI controller just dies. There's no magic on/off/reset switch. I wish there was, because I'd get them done same day and off the books. Have you checked your TV firmware is up to date? Android TV is not high up the list in priority updates. I'd make sure the TV is updated before replacing the main