I was practicing running beads on some thin aluminum flashing the other day and kept burning holes in it. It was odd because I set the dials as I'd done before when I had success. Used same gas flow rate, same filler, tungsten and all. Pressing the pedal beyond the arc start point would produce lots of hissing and popping. After some fussing around and troubleshooting, I discovered that the pedal was cranking out max amps when barely pressed. In other words, the first bit of travel after switching on the HF provides the same current as if the pedal were floored. The center of travel seems to be the 'zero' region where the minimum current is supplied or pure HF when low amps are set and the arc will not start due to insufficient current and work/tungsten cold. Thereafter, the current is more or less linear until I hit the end of travel or 'floored' region.

I take it something is misaligned in my pedal and hopefully can be fixed easily. It didn't exhibit this strange characteristic during the first several days I used my 250EX which leads me to believe that something slipped and the pot is misreferenced. In the meantime, I've been quickly mashing the pedal to the center of travel and slowly increasing toward 'floored' so I essentially have only the second half of the pedal travel to work with.

I want to be sure that opening the pedal won't void the warranty. If not, how do I go about cracking'er open? I have the new style pedal BTW. I'll test the resistance at various points when I find the pinout diagram (seen it here somewhere).

Tom

p.s.: It might just be my tired eyes but I don't see a "troubleshooting" or "tech support" section in the forum. Feel free to move this if there's a better place for it.