I would suggest talking with Hypertherm tech service directly. I cannot remember if we use exactly the same circuit on the 1250....but some of our units have a capacitor across the arc transferred relay contacts that in some cases needs to be removed from the circuit. Th tech service guys can help you out with that. You can also transfer an arc to the plate and monitor pins 12 and 14 to see if they are closing when the arc transfers.
We switched to the 1250 style torch quick connect for reliability reasons.....the earlier style had its share of failures in the field, mostly mechanical failures (things being dropped on the connector, machine being pulled around by the connector). The new system that will replace the 1250 (Powermax85) has a new quick disconnect that is very easy to use, and is protected and more rugged than the original 800 style design.
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