Wire feed won't stop running

[climbingchris]

I've got a sealey Power MIG 180 and the wire feed won't stop running, I've taken the torch off and it still runs, It stops when I switch it to the spot weld setting as you'd expect, but set to the normal setting it just keeps going.

It was working fine yesterday evening, got a bit of a birds nest in the feed so I stopped for the night, I went back to it this morning and it's playing silly games with me.

If I bridge between the two contacts ie pretent to be the trigger, the gas solenoid fires up and the wire feed changes speed.

Anyone got any ideas?

Thanks

Chris

 

[peterd51]

Hi,

I'm not familar with that set but is it possible to trace the wires from the torch switch to the inside of the case and disconnect them (mains power off while poking around in there!)?

If the motor still runs when you switch on then you have a problem with the electronics, possibly a relay stuck active. If it stops then it's a partial short on the torch switch, etc.

Regards
Peter

 

[Wozzaaah]

He says he's taken the torch off and it still does the same .
It sounds like a short inside, maybe even a bit of crud in the PCB?
Have a good poke about the circuit boards Chris, check for any damaged components or dirt built up on it.

 

[peterd51]

Hi,

Opps, sorry Chris, I missed that.

Muppetry in motion...

to the tune of the song by Johnny Tillotson!

Regards
Peter

 

[climbingchris]

The PCB is my suspect, it's been stored in a damp garage at some time so the components aren't in that great a state.

What's confusing me is the change in speed tot eh controller set speed when I pull the trigger, and it just creeps out when I don't. That suggests it's a short somewhere other than in the direct circuit via the trigger. But I haven't a clue where.

Sealy don't seam to make the set any more either so i don't know if I'll be able to get a spare board for it.

 

[Robotstar5]

It will take a bit of searching but there is someone on here who can repair boards to component level or PM Weldequip to see if he has a spare.
It sounds like a component is leaking (electrically) on the PCB and switching the wire feed on low speed until you pull the trigger then it works correctly.