Thermadyne inverter 155SE stick welder

[hayabusaman]

Hi All, When using the above welder I can't adjust the amperage dial, the dial moves but it won't reduce the amps, (I can use a 4mm rod on min setting) according to the manual there is 2 warning lights, 1 green(on) & 1 amber(fault) the green one is ok & the fault light is not lighting up, any ideas please?

 

[rtbcomp]

Sounds like a mechanical fault, either the knob has become detached from the shaft, shaft broken or the thread that moves the transformer core in and out has stripped, etc.