Wall control wiring shorted (or stuck button)

A LiftMaster or Chamberlain 1 up-arrow, 3 down-arrow flash points at the door-control circuit — the wall button and the wire feeding it — rather than the safety sensors. Either that wire is shorted (a pinched staple, a rub against metal) or the wall button itself is stuck in the closed position, so the opener behaves as if someone is holding the button down. It often shows up as an opener that runs on its own or won't respond to the remote.

The clean way to isolate it is to disconnect the wall-control wire at the motor head: if the 1-3 code clears, the fault is out in the button or its wire, and a new wall button (they're inexpensive) or a fresh wire run fixes it. If the code persists with that wire fully disconnected, the problem is inside the logic board — that's the point to call a tech rather than keep swapping parts.