[Amps] SB220 step start blows fuses

[Warren Volz]

All,

I’ve been restoring a SB220 and finally got to the testing stage this weekend. When I turned it on, the HV went up to ~1kV and then started to drop. Successive cycles of the power switch did nothing. Oddly, the meter lights and fan never started running. I looked at the bottom of the amp tonight and the 3A fuses I added to the W7RY step start board blew. What areas should I look at now to determine what is going wrong? I have both tubes in, and I believe I previously checked them for filament shorts. I’m worried the HV supply has an issue.

Any advice would be very much appreciated!

Thanks!

-Warren
KD5YPH