I checked the diodes and they all read the same OL in one direction and around. If power stays on then problem is in diodes / SCRs Or something between the diodes and the weld terminals.Thanks, that helped a lot! Turns out it was an interesting day as far as these welders go.
if breaker still trips transformer is bad. try finding the transformer leads to the diodes and disconnect them. the other 0.200 to 0.700 SCRs should read OL both ways. First test use multi meter is diode test mode. For first tests nothing needs to be disconnected. You need to check and see if any of the weld diodes are shorted. When Hobart was split ITW Hobart got all the manuals and they had them scanned. Call hobart or go to their web site and put in a request for a manual.
