26-12-2016, 04:39 PM
I just did a few more quick tests and have found my R12 is bang on spec resistance wise and there is a good connection to the Triode anode of ECH81. However HT side is dead. I tried pushing switches with the meter between HT and opposite side of R12 and zilch. There is no chance of any voltage drop of 100 odd volts on R12. Thus my job is clear: access the knob circuit and restore connection and clean all contact points. Any experiences of piano buttons welcome. I did notice R12 tab on HT side had some play.
