[Milsurplus] Capacitor failure? Resistor Failure? Suggestions?

[David Stinson]

----- Original Message ----- 
From: "Dean Kellogg" <kelloggd at uthscsa.edu>


> If I turn the power and emission switch to off, I can hear the beat 
> come back for a few seconds as the dynamotor rpm's drop.... 
> SO....does this sound like a capacitor problem...or a resistor problem?

Could be either, but most likely a cap.
As the B+ builds, the current to ground through the cap leakage
creates heat, which makes it leak more, which makes more heat etc.
Before long, your power's all going to heat the leaky cap.
Check the voltages out of the power supply.
If normal or close, look for a charred screen dropping resistor 
in one of the stages that's on the same B+ buss as the MO.
Could also be a resistor going hi-Z, but that's less likely because
the higher Z it goes, the less power it disappates, cooling it back off.