If you have a high speed Parkside polisher/engraver and it stops going.
The cause may be the legs have fallen off the output transistor( Tip122
TO220pkg). The repair is straight forward, the 5th screw is under the label
on the body. I'd recommend wiring in the replacement transistor with some
flexible 14/0076" wires, as the cause of failure is vibration in the
mounting. There's plent of room inside the case.