11-17-2013, 09:21 PM
If resistor 27 is completely open, that will certainly cause a problem, but then you would have no voltage at all on the plate (pin 2). You can try replacing it and see what happens.
I would also try to trace out the wiring to pin 7 and see why there is voltage present there. Pins 4 and 7 should be connected together inside the 7C6 tube, so there should be no voltage between them.
I would also try to trace out the wiring to pin 7 and see why there is voltage present there. Pins 4 and 7 should be connected together inside the 7C6 tube, so there should be no voltage between them.