Syncrowave 351 no HF start

[dveatch]

Have serial number KJ122640. Like the subject says, there is no HF start, interested only GTAW. Once struck the foot control works fine. I did check the switch in the foot control with an Ohm meter and it is fine. Since I do have control of the arc I figure the potentiometer is fine. Just to be sure cleaned the contactors and adjusted them for .008 (one was way over and the other way low). I do have arc on both contacts when striking. CB1 is not tripped.

After some googling around it seems the problem might be PC1, PC2 or maybe the PC3. If I had the component level schematics I could narrow down a bit more. Any additional thoughts to narrow this down? If I was to take a WAG my guess would be PC1 but trying to avoid shotgun maintenance.

[Aeronca41]

Schematic in the manual is next to useless. Watch eBay and see if you can find a technical manual for it; they show up occasionally for the older machines. Cruizer may be able to help if he sees this thread.