I hav found a thread on an idealarc 7723-c tig300/300 welder, I have one that worked ~4 years ago prior to being moved, now I try to stick weld and only tiny sparks when the rod contacts the work.
I have checked the 4 main diodes all god the 0-4 ohm pot is good, I have 14.7v on both dc -+, 30v on AC when selected , my machine is set up on 240v single phase, not sure what to check next