Any good maintainence blokes on here,who knows how to test the components inside a mig welder. :y

What's the problem with it?

They are pretty simple devices really. You have a DC supply to provide the arc, a feed motor to supply the wire, and a valve and regulator to supply the gas.

For the most basic checks, lift the idler on the wire feed so it doesn't feed wire, remove the shield from the torch and connect a multimeter on DC volts between the grounding wire and the feed nozzle.

When you press the trigger you should get 15-40 volts DC or thereabouts (depening on the output selected). You should also see the wheel on the wire feed rotating (speed should be variable by the wire feed knob on the front) and, with a full cylinder connected and the regulator properly set you should hear gas escaping from the nozzle.

If you have all 3 of the above you have the 3 things you need to weld. Install some wire and adjust the tension so it feeds steadily then try it on some scrap.

If it doesn't work under load suspect the rectifier diodes, which can easily be checked with a multimeter. If no output - diodes, transformer or choke (or a bad connection).

Let us know what the symptoms are and I'll have another think.

Kevin

.. and don't forget the fuse, especially if it's a >130 Amp device with a 13A plug on. ;)

Kevin Wood wrote on 20. Dec 2009 at 15:20:

.. and don't forget the fuse, especially if it's a >130 Amp device with a 13A plug on. ;)

Thanks for the info kevin,but it does actually weld and work ok,just that i dont know if its kicking out the power it should be,so really wanted to know how to test the rectifier and regulator etc.Welder is 170 amp sealy if it helps. :y