Hope this thread is not totally dead. The 3x switch strange behavior with oscillations at TP1 of A4 happened to me. I have two 13.2v hand tool nicads to power my 419.? I had wired in the +13 and -13 battery leads into the instrument,? I failed to connect the neutral wire between the batteries into the instrument power ground (eg. the case). With that wire added, the 3x insane behavior was gone.??
