The welder stopped throwing the breaker.

While I had it open, I cleaned up the inside of the wire feeder, thinking that an intermittent problem might be leakage. No compressed air was used.

I fed the wire with the trigger on the gun to fill the hose. It was almost to the gun when it quit feeding. If I use the jog button, the wire feeds with no problem. When I use the trigger on the gun, I can hear the gas solenoid activate, so the trigger is working. Wire feed does not work with trigger, does work with jog.

I've been working on understanding the schematic. It seems incomplete; I can follow the trigger wire only up to a point and then the schematic loses it.