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Lincoln tig 185

Posted: Sun Feb 13, 2011 11:46 pm
by manuelc
Today I bought a barely used Lincoln Precision 185 welder. When I got it home it was set at 135 amps. I ran a couple beads at and it worked fine. When I went to change amp settings the knob turns but the amp setting dropped to 4 and then after some spinning I got it up to 40 amps. The amp control is obviously not working. Can this be fixed or is it in the printed circuit board? I will call the local lincoln dealer tomorrow but I thought I might get an idea here tonight.
Thanks in advance

Re: Lincoln tig 185

Posted: Mon Feb 14, 2011 2:13 am
by Wobulate
manuelc,

Check the side of the knob to see if there is a set-screw.
> If so then gently pull the knob toward you so that you can see if there is a flat on the potentiometer shaft.
> If there is a flat then align the knobs set-screw with the flat on the shaft, push the knob away from you towards the machine until it stops and tighten the set screw.
> Check the potentiometer function to ensure it covers the range of the welder.

> If the knob and shaft are splined, pull the knob off and check the splines to see if they are stripped.
> If the splines are stripped then determine which you need to replace.

The knob might be mounted on the PCB, but it could also be panel mount.

Good Luck with your new welder. :)
Wob

Re: Lincoln tig 185

Posted: Mon Feb 14, 2011 11:32 am
by manuelc
Thanks wob for the reply,
That was the first thing I did hoping to find the knob was loose. It was tight.
So I took the knob off and just turn the shaft and the problem still exsists.
It just doesn't adj the amperage. The shaft goes directly in to the circuit board.
I have read where these circuit boards could be as much as $900.
So much for buying a used late model clean barely used welder.
I hope calling the local Lincoln dealer sheds some (cheap) light on my prob.
Thanks again

Re: Lincoln tig 185

Posted: Mon Feb 14, 2011 5:06 pm
by Wobulate
manuelc,

I would call Lincoln directly, but a dealer (if also a repair center) would be the next best. They want happy customers/users, so maybe they will help you out.
How old is the welder? The newer the better, and the lower the cost to repair should be.

Let us know what happens with Lincoln, I am particularly interested since I own a Precision TIG 225.

Wob

Re: Lincoln tig 185

Posted: Mon Feb 14, 2011 5:58 pm
by manuelc
I am going to take it in to the Lincoln dealer this week for a check up. I hope its something simple.
Ill let you know.
I have a question for you though. Does you amp control knob have a start and stop position or is it one of those infinite type control knob that will just turn continually?
I am curious. Mine has no start and stop it just turns round and round. There could be a clue there. If the knob was only designed to turn so many degrees low to high, then mine for sure is broke.
Thanks

Re: Lincoln tig 185

Posted: Tue Feb 15, 2011 1:29 am
by Wobulate
manuelc,

I believe mine is also an infinitely variable control as it has little to know resistance.
Typically that is indicative of an optical encoder on the PCB.

So, the motion of your control is similar to mine.

Wob

Re: Lincoln tig 185

Posted: Tue Feb 15, 2011 12:45 pm
by manuelc
Thanks WOB,
I am going to take it in this afternoon to the Lincoln dealer in Modesto. Good people and I can trust them to give me the straight scoop.
The bummer is I have waited for quite a while to get a tig set up. Then I get one and it has probs. The worst thing is that the guy I bought it from ( a policeman) knew it had a prob. The machine is eceptionally clean so I paid top dollar for it.
Well if you buy used I guesse it's buyer beware. All I know is I work on a different set of principals.
Thanks for you help
I'll let you know.
Manuel

Re: Lincoln tig 185

Posted: Sat Feb 26, 2011 2:44 am
by manuelc
Wob,
Just thought I would fill you in on my PC Board issue.
Found a welding supply and repair company right NEXT DOOR to where I work. They have a guy in san jose that repairs all their boards. I will drop it off (next door) on Monday and should have it back by end of week
So all is not lost. Thanks for your assistance, I appreciate it.
Manuel