Have not seen this one but I would start with checking your battery is fully charged. After that I would ring the support at SA. They are really good and will walk you through the problem. It could be anything from the mercury switch, the top or bottom circuit board. If it urns out to be he bottom circuit board I may have a new one here.
Oh check the foot pedal. Open it up make sure the motor controls are not corroded. Good luck ted
