[morzh]

I was hoping that was a bad 42 tube.

Now is the time to check the caps.

1) First start with caps attached to the ends of the output transformer primary (plates of the 42s).
2) Also the electrolytic cap at the output lead of the field coil (cannot make out number) - where it ges to the output transformer CT.

3) Also caps 8 and the 33.

Start from powered down unplugged state and check every cap with ohmmeter to GND.

4) Last thing: check the output transformer primary (any lead) to GND. Need to eliminate the insulation breakdown.

5) Is the speaker pluggable? if yes unplug and meaure the volage at the output of the field coil when powered up.
ONCE DONE PWER DOWN AND PLUG THE SPEAKER BACK TO DISCHARGE CAPS !!!