Well since no one has tried this evidently I forged ahead. Getting the circuit board out was easy. Remove all the knobs, remove all the nuts on the jacks (14mm) and pots (10mm) and two screws holding the XLR connector, unplug five connectors and it's out. On inspection of the solder connections on the foot switch jack they all 'looked' fine. Looking at the other jacks the effects send jack had an obviously bad solder on one of the legs. A couple of the other jack solders looked suspect but not nearly as bad. I made the decision to de-solder and re-solder every connection on every jack. Four per so 20 total. It took about 30-45 minutes or so. Put everything back together, plugged in, powered on, no sound. Crap, wait, I forgot to turn the volume up on the bass. Sound. I played for about 45 minutes with no problems. I was also have a problem with the amp cutting out occasionally, that seems to be fixed too. The jacks are so simple that unless something physically broke I can't imaging anything going wrong with one. Anyway, it seems to have been a successful fix and time well spent. Hope this helps someone.
Don
