Pin7 is the plate connector.
Examine the tubesocket to see if there is any chance that the pin 7 gets no connection, replace socket if in doubt.
Follow the wire soldered on pin 7, reflow solder.
When all caps are discharged, connect a ohmmeter between pin 7 and the point between R11 and R12 , note the value ,
then gently move the wire from the transformer side to side to see if the value changes, if so there is a problem with
the wire from transformer.
But would guess there is a bad solder on pin 7
Examine the tubesocket to see if there is any chance that the pin 7 gets no connection, replace socket if in doubt.
Follow the wire soldered on pin 7, reflow solder.
When all caps are discharged, connect a ohmmeter between pin 7 and the point between R11 and R12 , note the value ,
then gently move the wire from the transformer side to side to see if the value changes, if so there is a problem with
the wire from transformer.
But would guess there is a bad solder on pin 7
It's very dangerous to the health of the valve's screen grid G2 to operate without pin 7 (anode) connected. You need to find and fix this problem before much more operating time. The valve is likely already somewhat damaged.
All good fortune,
Chris
All good fortune,
Chris
More bad solder joints, on bad tube socket pins.
Certainly not a bad power transformer.
Certainly not a bad power transformer.
Problem seems to be solved by filing down the contacts a little in the sockets and redoing solder to sockets. I also filed the pins a little to reveal their shinny metal. Not had it gone quiet yet in the last 24 hrs.