One more 180SD problem?

[Little]

I have a 180SD bought in 1999 that I love to use. It has had very little use. It has a bad habit of not being able to modulate the amperage. It will blow a hole in a 1" square thinwall tube in about a half second no matter where the amp dial is set. I asked a real weldor here who suggested it simply needed blowing out. I took off the covers and blew it out good and it worked well. This has now happened twice more, covers pulled and compressed air blown through the contacts and the selector switch. I tried a weld today and the problem is back. It seems like something has gone TU. The first time it happened, I asked and got a reply from Jeff Johnson at Miller who said the only things to go wrong were the PC1 or the HD1. Which is more likely to be bad and how bad ($) do I have to want it?
I thank anyone who is willing to take a guess.
Little

[ASKANDY]

Also could be your foot pedal control losing the gnd reference and it will run up to max as soon as the pedal is pressed. See if a friend has one you could try or see if your local dealer would lend you one to see if that is your issue. I had one of these go bad on a Dynasty set up and it was a small cut in the control cable that severed the wire. Because your problem is intermittent, I would really look there or a loose wire or terminal.

Good luck

Andy

[Dan Payne]

180 SD Problem

I also have a 180SD sycrowave machine that is currently in the shop having its circuit boards replaced. My problem was getting a arc at the tig torch without pressing on the pedal and eventually the machine just quit. Like you this machine had very very little use on it. The diagnosis is bad circuit boards. Very expensive to fix.

[Little]

Well, I just checked out the foot control. It shows no broken continuity in any of the wires to the machine. On recall, the first time this happened, it was in the stick weld mode.
Would I be mistaken to suspect the amp control switch? Since it is a part of the pc board, is this a replaceable part?
Thanks for all the help and Andy, thanks for a great board.
Little

[Too_Many_Tools]

....The diagnosis is bad circuit boards. Very expensive to fix....

Sorry to hear about the problems.

Would you mind letting us know how much this will be costing you?

I have a new 180SD in the box that will likely get very little usage during its warranty period.

Thanks

TMT

I also have a 180SD sycrowave machine that is currently in the shop having its circuit boards replaced. My problem was getting a arc at the tig torch without pressing on the pedal and eventually the machine just quit. Like you this machine had very very little use on it. The diagnosis is bad circuit boards. Very expensive to fix.

[cruizer]

You have a sticking relay on your circuit board, very common, the relay costs about 6 bucks at an electonics shop, when you blew the unit out, you probably bumped it. Or you could pay the $450 buck for a new board.

[Little]

Hey, Cruizer, Thanks for the tip. I find only 2 small (3/4" square) doobers (3 poles on 2 sides each) that might be relays. Do I check these with them on the board? Or the better question is how do I check them? The board is out of the machine.
I took the board to the repair place today, but they couldn't check it while it was out of the machine.
Little

[Mike W]

Hi Little, can you take a picture of the board?

[Little]

Hi Little, can you take a picture of the board?

I might can do that. I've tried posting pics with spotty results.
We'll see if I can decipher how in the AM.

[Little]

Shot of small board and large board.

[Mike W]

I took a quick look, had to magnify the pics. I didn't see any relays, at least the normal looking ones. I once took a circuit board in a Lincoln high freq box and made a schematic so I could trouble shoot it. Any idea of what a replacement board would cost?

[Little]

I'm afraid it'll be in the $3-500 range (yikes ) I guess I'll just suck it up and take the unit to the shop.
Thanks for all your help and also for a great forum.
Little

[Little]

Good news! It's working again! I'll run it till it breaks again then to the shop it goes.
Thanks again for all your help
Little