What does it mean when even with the Potentiometer completely disconnected welder still over-burns ,almost killing the motor and melting the rod like spaghetti?

 

It means you have a problem with current control, voltage control, or both, and maybe more.

 

It means you need to tell us your location, make and model of welder so we know where your from and what you're talking about.

 

Ok great .My name is Ken and Ilive in S.F.East Bay Area.Im working on my Miller Blue Star 180K,witch is a CC-DC Welder/Generator with a single turn potentiometer that I have replaced and two more 28 turn on the board.

 

Ok great .My name is Ken and Ilive in S.F.East Bay Area.Im working on my Miller Blue Star 180K,witch is a CC-DC Welder/Generator with a single turn potentiometer that I have replaced and two more 28 turn on the board.

your output pwr transistors may have shorted

 

Unfortunately more than likely your field current regulator board went out but there are schematics for your machine that will give you a good reference point to work from.

The nearest online reference I can find is this. https://www.millerwelds.com/files/owners-manuals/O436_MIL.pdf

See diagram 11 - 3 for your boards basic circuit layout.

 

Ok now I788 went over the board with the ohmmeter set on beep....Some of the components beep some jst show a reading And some do nothing.Does that mean anything as far as figuring out which one or ones are bad?

 

Is this something I can fix?

 

Unfortunately if you are not familiar with how the individual components work and how to check them properly, no it's not likely something you can easily fix yourself.

From what I can see of the schematic they give in the online owners manual it has little or no reference to what the values of any of the components are so I can't even reverse engineer the circuits working process to help you out.

 

Do you think it would be worth it to send out for repair?

 

It's your machine and your call. Do you value it enough to justify the repair costs that may be involved?

I used to work as a service tech in a welding supply center and I ran into a lot of people who wouldn't spend the $50 - several hundred it would take to repair overall still good solid machines that were worth 10 times or more the repair bill estimates. What they would do is sell me the machines for pennies on the dollar then buy brand new ones to which I would fix their machine at home in my free time and resell it for some pretty good profits while still being way under the common resale values.

I picked up a few $3000+ machines for $50 - $100 then spent 50 - $200 to fix them then sold for $1000 while the typical price for said used repaired units was pushing $1500 or more.

 

Well ya thats what I think is it would still be a good machine for a couple hundred bucks which is a lot less than picking up even a used machine ...Ive seen some pretty good deals but after you ship it???And then I would be stuck with a welder that's too good to scrap ,but difficult to sell not working...Any way ,thanks for the info.

 

good news ...I have found a new board and it solved my problem....now I am having a problem with the Run /Idle not winding down.