06-08-2008, 10:04 AM
I am slowly learning to use my old Thunderbolt, but sometimes it seems "hotter" for the same Amps on AC vs DC. I was looking at the schematic and the SCR has 4 diodes inside as a full-wave rectifier. I started wondering if one of those diodes was "open" (as opposed to shorted) it looks like the welder would continue to work but the current would be weaker. Has anyone ever had any experience with an SCR getting weak but still working?