Old Shure ULXP4 pack entering Master List Mode by itself. Possible fix?
See title. We use these transmitters for educational/regional theatre productions. One of them is entering Master List Mode on its own. They're quite old, so I'm guessing an internal component is causing extended phantom Set button presses. We've ruled out this being a case of the pack being pressed up against a performer's body when clipped to a bra/mic belt.
I am also wondering about a possible, if cumbersome fix, I might've found. If the transmitter is position locked, and I go to switch it off, the display reads "PO L." When the screen display has this message, the pack never enters Master List Mode regardless of how long the Set button is held. Does anyone have any insight as to whether or not the PO L message display is given some kind of priority over other button presses on the transmitter itself? We're not exactly in a position to buyy new wireless mics, so even an out-there fix like this would help.
If anyone has any other fixes for this, I'd love to hear them as well. I don't think these transmitters are even being serviced anymore for repairs.