I've got a supermig the wire feed wont run unless the spot weld timer is in the 'off' position and when it does run it wont stop when i release the trigger. Dont know if anyone has any ideas??
Do you still get welding current and gas when the trigger is released? If so I'd be looking at a faulty trigger.
If not, then the fault is most likely with the motor control board, and in particular the motor drive transistor/thyristor or whatever that machine uses.
That said, do you have to squeeze the trigger to start the wire feed, or does it start as soon as you switch on?
havent yet connected the gas to it and yes the wire will only start feeding when the trigger is pulled. i did wonder if it was the trigger but thought if it was stuck on then it would run all the time.
So if you switch it off at the mains it stops feeding (obviously), switch on, doesn't feed, pull trigger feeds, release trigger, doesn't stop feeding.
That and the timer switch symptoms points towards a control board fault.
We really need the circuit diagram.
With the unit unplugged from the mains, a quick blow our with compressed air may help, a good look round for loose wires and have a look on the control board for signs of burning.
Not sure if this works or not but i had the same problem on a Hobart 400 migset, I got an airline and blower and i gave the curcuit boards a good blast, in all the vents and had a good 10 minutes blowing all the crap which does get acummulated over the years. Worked a treat after that.
You'd be suprised especially if you do a lot of sanding, grinding near your welder