Contactor error, but it's ok!! another problem?

[500 Mondial]

Hi, my Elektron Multimig 300 has developed a fault.

I was welding over the weekend, nothing out of the ordinary happening in fact the welder was extremely happy. I switch off and returned a short while later, start welding again and all still good, finish first weld and release the trigger and nothing, but the wire is live, the machine says '' main contactor error ‘’ so I dismantle the contactor ( which is fine and very clean, coil good ) and refit, still the same problem, one weld then an error code appears, I have tried a new torch, I have visibly checked all the boards and tested mosfets and capacitors everything seems ok.

I feel this is perhaps something obvious but I can’t see it, I presume the contactor coil is not being told to release as there is still 46v and the contactor is operating, this information is coming from the non potted board I think.

Ever come across this type of fault?, Is there anything else I can check it would be most appreciated, if I can’t get this going again I fear I will have to scrap it as the value is past professional repair ( and my workshop is very small to keep cool stuff that doesn’t work )

Cheers, Sean.

 

[eddie49]

From what I have found, the Elektron Multimig 300 is a 3-phase inverter with digital controls.
It sounds like the fault is due to an error in the control circuit, rather than the MOSFET power side. Do you have a manual for it? Is there any mention of a "system reset"?

If the machine has any functions that would drive the Contactor automatically, such as 2T/4T, Spot, Stitch, or Burnback, try setting, adjusting, then resetting those modes ( if the control panel still allows you to do that, despite the error... ).

The "control" board probably has a large multi-pin microprocessor chip on it. Try removing and replacing all the connections to that board, checking it for dry joints, and putting pressure on it whilst powered up.

 

[500 Mondial]

Thanks Eddie, I will try your suggestions, need to replace the lifted resistors first.

So I get the board out and go through testing what I can, no dry solder no cracks as far as I can see, but there are a bunch of 10 and 1 single 470ohm resistors, these all measure 5.6 ohms each ( lifted too ), there are two 47ohm resistors banking these and they measure 1ohm, secret batch marking to confuse? can 13 resistors be completely out of spec.
The 11 definitely marked, yellow, violet, brown, gold and the two are marked yellow, violet, black, gold.

 

[angellonewolf]

did you remove 1 leg to do the tests on the resisters