Portamig 255 help please

[Greenhills]

Got a portamig 255 that I bought way back in the day and used mainly sticking old cars back together.
Sometime ago it started playing up. Stuttering etc. I sent it to the local shop and it was serviced and given a clean bill of health..
Sadly I'm still getting the stuttering ( feels like the wire hits the steel but no arc ) it then sticks in the torch andci have to teist the torch to release it. This means I'm getting spots of weld not flowing into the panel :/
This is not constantly happening, just often enough to be very annoying..
I'm looking at getting a new welder which would be a shame as I'm sure there must be a cure for this :/

.6 or .8 wire, various power levels, new Binzel 4m torch. I tend to weld in spots hot n fast. Currently using level 4 on 1mm panel..
Anyone help?
Thank you..

 

[mike 109444]

With what you have checked so far, you might want to check the work ground clamp/cable/plug and socket on the welder (including inside machine on back of socket).

 

[MetalMonkey]

These are pretty basic machines, so whatever is wrong with it will very likely be fixable.
Check everything for loose connections as a first port of call. Do you have a spare torch you can swap over to eliminate that?
When you pull the trigger do you hear the contactor clicking in when the problem occurs?

You could also speak to Technical Arc (the manufacturer) for help, they usually offer a repair service.

I had an issue with a 275 which went back to them under warranty with an intermittent wire feed fault, they didn’t actually find the problem but it turned out to be a dry solder joint on the control board.
There is only the one circuit board in the machine – everything else is transformers, contactors and switches. So it should be fairly easy to narrow down the issue.
Even if you had to replace the entire circuit board you would still be down a lot less than a new machine.

The biggest hurdle is if the problem doesn’t occur consistently there is only so much time and effort a repair place can put in to trying replicate the issue to find the fault, whereas if you can try and narrow it down as and when you experience it you might have a better chance of success.

 

[brewdexta]

I've got a Portamig 185. I had similar symptoms recently, turned out to be the earth lead. The lead to the clamp had visible heat damage, the insulation was melting. The cable crimp at the clamp end had a 16mm hole for an 8mm bolt, so replaced that with a new crimp with an 8mm hole. At the dinse plug end, the boot was perished so when you turned it to engage the dinse plug in the socket, the boot was rotating, not the plug, so this caused a bad connection. I took the boot off and turned it with a pair of pliers. I have a new clamp as the stock clamp is a bit carp, and I've got 5m of 25mm2 cable and a Binzel dinse plug on order, that should fix it.