Hoffman 610 Lost B+

[Doug66]

Correction: I misread the schematic. The 560ohm resistor that is pulling the voltage down on V105 is R113. It goes to pin 8 in parallel with a 20uf electrolytic.

With R113 connected, and R178 disconnected, I have about 80V.
With both R113 and R178 connected, I have about 25V B+.
With both R113 and R178 disconnected, I have the required 260V B+.

[old_coot88]

(With the set off) check resistance from centertap of power xfmr. to ground. What reading do you get? It should vary a bit with the focus control setting.