[Amps] SB220 step start blows fuses

[Warren Volz]

Thank you for the flood of good suggestions. I'm getting closer.

Without tubes and with the HV transformer unplugged, the fan and meter lights work. In addition, the step-start fuses don’t blow!

That leads me to suspect the tubes + HV supply. I checked the windings on the HV transformer to look for shorts:

BLK-YEL = .7 Ohm
BLK-BLKYEL = .6 Ohm
BLKYEL-YEL = 0 Ohm
BLKGRN - BLU = .8 Ohm
BLKGRN - BLKRED = .6 Ohm
BLU - BLKRED = 0 Ohm

Do any of those look off?

Also, would these steps (or something similar) make sense?

1) Re-enable HV supply, power on, if fuses are ok power off and go to step 2
2) Once HV dissipates, add tube 1, if fuses are ok, power off and go to step 3
3) Assume tube 2 is shorted, else tube 1 is bad

-Warren