If you have an audio oscillator and ac voltmeter handy, inject 60Hz at 1V into the primary and measure the secondary. That should help you see if there's a ratio/shorted turns problem.
Next would be to slowly bring the xfmr up to full input voltage with a variac, with a light secondary load. If it survives the voltage test then the trouble is likely in the load somewhere (rectifier, etc.). g Dave Aabye wrote: > > Good morning all, > > I need some advice. > > Earlier today my Viking 500 tripped off with the familiar odor that we > have all come to dread. I only lost HV. > > After I got the cover off the PS-Mod unit, I was surprised to see > nothing unusual. Then I started sniffing, and that led me to the HV end > of the plate transformer. I removed the end cover and again saw nothing > unusual....only the odor, which by then was beginning to dissipate. > > Resistance measurements lead me to think that some windings may be > shorted. One side to center tap reads 110 ohms. The other reads 95. > The manual says 100 on either side. The HV secondary shows infinite > resistance to ground, but that is with no juice applied. > > What I'm wondering is whether the 15 ohm difference is conclusive. If > not, what other tests might I make without risking further damage? > > Thanks in advance for any advice, > > Dave, W4QCU > Oak Ridge, TN
