TPC Aux Input Terminals

I was just corresponding with someone who upgraded his TPC with a modification I developed a while back.  That reminded me of something that every TPC owner should do -

REMOVE THE TWO SCREWS ON THE "AUX INPUT" TERMINALS AND THROW THEM AWAY!!!!!

I have had to repair several units that had damage to the Aux Input receiver chip.  Unfortunately, this damage also blocks the normal Serial Input COM path, killing the unit.  I must assume that the user somehow applied a voltage to the Aux pins and wiped out the chip.  Do yourself a favor and remove the screws.  I do that as SOP whenever a unit comes in for repair.