Something has gone haywire in the old Dynatorch. After homing the machine the arc voltage spirals up and displays +++. It starts at ??? > 125 > 181 >219 > 244 > +++. When run it pierces normal and then scrubs the torch into the plate. The voltage is stuck on +++. I seem to recall it always displaying --- when idle. Same issue with the plasma on or off.

It appears the there may be an issue with the isolation board. See the attached image.

Does anyone have any schematics of the controller?

Attachment 445832