03-30-2015, 07:39 AM
The 240K resistor supply's the high voltage to the 6Q7. You said that you have 78v on pin 3 of the 6Q7 that would indicate that the resistor is ok. If there was a short or bad connection you wouldn't have the 78v on pin 3.
I'm thinking that the 6Q7 is bad or there is a bad connection at the socket. Try Measuring the pin 3 voltage (78v) not at the solder lug but at the tube pin. Place the meter probe into the center eyelet only touching the pin of the tube. Something else to try is reflowing the solder on the pins of the 6Q7. Also try injecting an audio signal (from audio generator , tuner, ipod, computer, ect) though a .01 cap and gnd to pin 5 of the 6F6.
Terry
I'm thinking that the 6Q7 is bad or there is a bad connection at the socket. Try Measuring the pin 3 voltage (78v) not at the solder lug but at the tube pin. Place the meter probe into the center eyelet only touching the pin of the tube. Something else to try is reflowing the solder on the pins of the 6Q7. Also try injecting an audio signal (from audio generator , tuner, ipod, computer, ect) though a .01 cap and gnd to pin 5 of the 6F6.
Terry
