Most of these machines (would have to have serial number to be sure) will not feed if their is no output voltage, since part of the motor voltage comes from the arc voltage. So, I would suspect broken wires, either in the work lead or the gun. If it arcs just a little, probably the gun. One place the work lead breaks is right at the back of the clamp. Pull on the insulation and see if it "stretches". If so, the wire there is broken.
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Most of these machines (would have to have serial number to be sure) will not feed if their is no output voltage, since part of the motor voltage comes from the arc voltage.
So, I would suspect broken wires, either in the work lead or the gun. If it arcs just a little, probably the gun. One place the work lead breaks is right at the back of the clamp. Pull on the insulation and see if it "stretches". If so, the wire there is broken.