Fuse F203 fuses the power to the tube heaters... however if the pilot light is on that fuse is OK.
A diode full-wave-bridge consisting of D206, D207, D208, and D209 rectify the power for the tube heaters. A failure of one or more of these would cause the problem.
C210, C211, C212, and C213 (1000 mfd/35 volts each) are suspect and R213 (1 ohm 5 watts) series resistor.
ALSO look for circuit board cracks through the traces and BAD solder, especially on the resistor as they sometimes get hot and solder degrades.
Answers & Comments
Fuse F203 fuses the power to the tube heaters... however if the pilot light is on that fuse is OK.
A diode full-wave-bridge consisting of D206, D207, D208, and D209 rectify the power for the tube heaters. A failure of one or more of these would cause the problem.
C210, C211, C212, and C213 (1000 mfd/35 volts each) are suspect and R213 (1 ohm 5 watts) series resistor.
ALSO look for circuit board cracks through the traces and BAD solder, especially on the resistor as they sometimes get hot and solder degrades.
I have schematic if you need it... email me.