call miller tech support. have your serial number and full model name at hand. ask them the same question. if you can figure out the number of the resistor it might help.
They won't help repair the pcb. But you should be able to get from them want that resistor does, If the cause is on the pcb or off the pcb. And where to look if off pcb.

 

Call these guys.

or send email.

http://www.innovatcorp.com/

 

It's a power resistor, looks like a wire wound . . . believe it or not, despite being that cooked, it is likely way off value, but may not be totally failed, and thus how it still works . . .

- Tim

 

Yea, Tim. It's amazing I've seen some wire wound resistors that looked absolutely smoked, even broken in appearance yet still functioned.

Hopefully nothing else is fried. Can be tricky attempting a repair. Taking it out might actually damage something else in the process. Repair on that board may only be a couple few hundred bux. Hard to say tho.

 

That's a through hole board, so unless the board delaminated from the heat, I would not think that would be too bad, and likely the foil is pretty beefy (and for power stuff like that, heavy flying ties will repair bad traces easily). And, myself, to change that on a working board, I'd be mad as hell to be charged a couple hundred . . . the part is likely $2 or so, and maybe 10 minutes if you don't have to pull the board as well.

 

A place like Galco, when they do a board repair replace a lot of the major components on them too. At least that's been my experience with them. This looks pretty straightforward, prolly be ok.

I just know how my luck with stuff like that goes :laugh:

 

Well, that's rework vs repair . . . so makes more sense that way. Compared to some of the stuff I've worked on, that looks pretty good, actually . . . and not much of anything on that board that ages other than a few inexpensive small capacitors, at least that I can see.

- Tim

 

i have a millermatic 250x and the circuit card on those were junk. I called miller techs and they were able to give me the correct part number for the card. The old card design, was upgraded and superseded the old part number. Then i went online and found one for $450. good luck!

 

Thanks for all the info. I did call Miller twice. The first time they said it was resistor #159 1/4 watt 82.5 kohm and # 160 1/4 watt 332 kohm. He said it look like it was involved with the gun trigger 15v circuit and it was probably caused due to a shorted gun but assured me if the welder was still operating, they were still functional. He suggested to keep welding and if in the future they gave me problems to have them replaced.
So I went online and tried to order some so I would have them on hand and realized they didn't look like anything like the ones Miller suggested. The one on the right I could read the codes and apperently it is a 5 watt 5 resistor ohm wire wound tubular resistor.
I called Miller back, talked to a different tech and he gave me the same resistors as the first tech. I told him what I found out and he checked the board material list and there was a 5w 5 ohm resistor on the list, but only one. He suggested metering the resistors to confirm their value before they stop functioning so I would know the values for sure. The one on the right was 5 ohms and the one on the left I couldn't read but I don't know if I had a good connection or not. The board seems to have a coating on it.

 

I guess since it's the advice of both techs I will continue welding with it and deal with it if it stops working. I found this place would will fix the board pretty cheap if worse comes to worse.
http://www.plccenter.ca/en-CA/Searc...CA/Search/Advanced?Manufacturer=MILLER ELECTRIC&TopCategoryId=19&CategoryId=163

They charge $389 Canadian ($282 US) to rebuild it with a 2 year warranty if I can't just get them to replace the two resistors.

 

Here is a picture of the back. View attachment 1350651

I tip my hat to Miller customer service for spending the time to help me with a 20 year old welder that I'm probably the 3rd or 4th owner. Does anybody know we're I could get a copy of the schematics for my board?

 

Re: I need help with a Millermatic 250 Circuit Board Please

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