I've had a 788 for about 6 years now and love it. Had the same problem and corrected it by replacing the on/off switch and

going to a foot pedal. When I replaced the switch I tore it apart and looked it over and the points that make contact

were arched up really bad. Looking the switch over I figure it is not made heavy enough for the amount of times I cycle it.

Did the replacement 4 years ago and haven't had a problem with it since.

Bill McAllister

Florence, SC