[68ragtop]

So I bought a New Miller Syncrowave 180SD back in the summer of 2002. Used it 100% for smaller carbon steel work & nothing else. Then had to repair some aluminum & having zero experience with it, I just kept trying things until I found it would weld in DC mode, setting the polarity to electrode (+) this worked pretty well for small stuff, but the aluminum had to be crazy stupid clean. So I continued on thinking nothing of it.

Then about a year ago, I was trying to weld up something a little thicker in aluminum. Just too much heat being passed into the tungsten & it would blow it apart after a short amount of work time. I had a friend stop over who has a lot of seat time welding aluminum. First thing he did was flip the switch over to A/C & guess what. Almost no output from the welder. I told him I was never able to weld anything in A/C & He quickly determined there was something wrong with the welder. What the heck? All these years I assumed A/C was just for stick welding, so I never tried it further.

It will freq start an arc in A/C mode, but its almost as if there is only 10% power, or a bad ground. I took the cover off & adjusted the gap on the points, but that didn't do anything. Good 220 connection with ground.

Any thoughts on trouble shooting further? I would assume this welder should be able to do Aluminum A/C?

What bugs me is this has likely been this way since the day I bought it.