Hi ggmkemzzz, sorry for the late reply. I didn't see this question and it didn't show up as a new post for me. It's probably because i did some upgrades. Anyways, my apologies.
Just glancing at the manual for that welder, if you look at figure 8-3 circuit diagram for automatic idle control circuit board PC1, it shows each of the individual board components which you're probably already aware of. If you scroll further down you'll see in the parts lists each of the individual boards with a breakdown of all the components and their respective values.
Unfortunately troubleshooting at the board level can be a pain. The first thing to do is to look for burnt wires/traces, or burned components. If you don't find anything visibly wrong, then you'll need to check each component individually to see if it's within range of it's stated values listed in the parts breakdown.
If there's a step by step guide for it, i'm not aware of one. The dealers may have something like that.
Hope that helps, although you've probably got it fixed by now!