Miller syncrowave 200 help I have a miller syncrowave 200. The machine was working fine but all of sudden started to melt the tungsten in ac mode. I sent out the circuit board to get tested and it tested good. I changed the bottle of argon but still same thing. I think it’s stuck in dc + while in ac...

Miller syncrowave 200 help I have a miller syncrowave 200. The machine was working fine but all of sudden started to melt the tungsten in ac mode. I sent out the circuit board to get tested and it tested good. I changed the bottle of argon but still same thing. I think it’s stuck in dc + while in ac...