thereverendgpat

If your "work around" involves tapping, it sounds like a bad solder joint or a cracked board. Neither is good in this type of printed circuit board era. The black box message is more than likely an indicator of the PCU intermittently shorting out. This can be a direct result of a bad solder joint or a disruption in the current path. The fix may be more than the amp is worth. Lots of good and new and used amps out there. Time for a shopping trip?