Rob, just tried your 3 added parts and it still does the continous sparking. It's coming from the pic in the software.

Jeff, also tried the small cap at that juncton, also a no go. So it is in the software. Stuck somewhere in a loop until it sees a change of the hall signal because if you move the magnet away from the sensor, it then stops. Somewhere in that control loop lies the problem.
I replaced the burned out transistor and all is well with the HV board again. Ran the engine and it's fine. Just can't stop the magnet under the sensor or you get a buzz of sparks and the transistor heats up cause it is supplying too much current to the oscillator circuit.
Somewhere there's a problem with it, Maybe Jake can find it.


John