Perhaps a crude fix for the flaky 5V supply would be
to add 5 self tapping
screws to the area where the finger drumming works. Although I'm sure Tony
would point out that what's really needed are 4 self tapping screws and a
thumbscrew...
Actaully I'm more likely to suggest yoy resolder that darn dry joint, and
go over others in the area. Preferably before soemthing in the sense
circuit goes open and the output jumps to 15V or whatever!
-tony