cruizer - Thank you for responding!
I will check those voltages this weekend (hopefully). Right now I'm out of town for work. Please confirm with welder on and set to HF start mode:
RC1-1 to RC1-3 voltage at idle is 325V AC or DC?
RC2-1 to RC2-2 should +15 VDC pedal up?
RC2-1 to RC2-2 should 0 VDC pedal down?
I don't have a scope right so I can't check the 700Hz now but I can buy a scope if need be. I'd rather invest the $500 in a scope and fix the card for $15... but I will take your advice as we work through this. Thanks!