When I hit the foot pedal I get absolutely nothing. No arc, no gas. When I switch the machine from TIG to Stick (but with the TIG torch still hooked up), I get gas flow while I'm switching it, and when it is switched I can scratch an arc with the tungsten.
I checked all the cable connections, everything is good. I powered down the welder and unplugged it for a minute or so, plugged it back in and that didn't help.
I thought it might be the foot pedal. I tore it apart, it is a 5 wire pedal and there are two components in it. A limit switch and a 1K Ohm potentiometer. I checked the limit switch for continuity, it is good. I checked the resistance on the pot, it changes smoothly from 0-1K ohms across wires 1 and 2, and it changes smoothly from 1K-0 ohms across wires 2 and 3. It seems like this is right.
Anybody ever have a similar problem or have any other ideas? My next step is to investigate inside of the welder but I don't really know what to look for.