[Amps] SB220 step start blows fuses
warren at warrenvolz.com
Thu Jul 6 02:07:50 EDT 2017
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
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