Hi, I confess I don't know if I've inherited this problem or only just realized it. It's always been a bit hit and miss on the control front.
It strikes a hf arc on AC and sparks up, but when you alter the amerage dial on the front, the amp meter and welding current supplied doesnt seem to change. Ive taken off the top and checked the large power rheostat with a multimeter, and it seems to range from 0 - 6 ohms as you sweep through the range. Ive traced the wiring back to various connectors and nothing seems amiss or obviously broken so now I'm stumped. Switching the range switch between modes eg 30-200 gets me 30amps, 100-375 gets me 100amps so it would seem that changing the tappings on the transformer via the big power wafer switch work but not the fine power adjustment?
I have no recollection of ever seeing the needle move on the ammeter as I turn the power, I did think it was just broken but its awkward to see anyway as it only reads when the torch is lit.
There is only a couple pcb's on it and a big bank of large relays, and the pcb's have a handful at most of discreet components so fingers crossed it should be repairable if I can find the issue.
Any pointers where to look next? I have no manual or circuit diagram for this machine, as pointed out in the past it's not the rebadged murex model.
On the plus side, at least I've traced the problem with my pedal not varying current, the machine itself is the culprit. Ive tried it sans pedal too as a check already.
It strikes a hf arc on AC and sparks up, but when you alter the amerage dial on the front, the amp meter and welding current supplied doesnt seem to change. Ive taken off the top and checked the large power rheostat with a multimeter, and it seems to range from 0 - 6 ohms as you sweep through the range. Ive traced the wiring back to various connectors and nothing seems amiss or obviously broken so now I'm stumped. Switching the range switch between modes eg 30-200 gets me 30amps, 100-375 gets me 100amps so it would seem that changing the tappings on the transformer via the big power wafer switch work but not the fine power adjustment?
I have no recollection of ever seeing the needle move on the ammeter as I turn the power, I did think it was just broken but its awkward to see anyway as it only reads when the torch is lit.
There is only a couple pcb's on it and a big bank of large relays, and the pcb's have a handful at most of discreet components so fingers crossed it should be repairable if I can find the issue.
Any pointers where to look next? I have no manual or circuit diagram for this machine, as pointed out in the past it's not the rebadged murex model.
On the plus side, at least I've traced the problem with my pedal not varying current, the machine itself is the culprit. Ive tried it sans pedal too as a check already.