Scott,
The damaged resistor is on the +15 volt line, but the foot switch issue you mention makes me think of another (ghost) short I had some while ago, which happened only when the Yamaha foot controller was connected on the back.Since then, It stayed unplugged the time to deal with that, but never really analysed the cause behind it in the end...Well, one thing at a time, for now it's the PSU first ;-)