Hobart LxiH. Customer thinks electrician may have hooked up three phase to the unit (it is a single phase 240 unit). Will not start when on button pressed. Some troubleshooting found control transformer was not outputting 12 volts. Control transformer replaced. Unit still will not power on. Metered out membrane buttons, on, off and wash buttons work. Metered high limit, high limit circuit is closed. Swapped out control and output boards with known good boards, unit still will not boot. What in the world am I missing here.
If the primary, then YES, an incoming power issued.
If the secondary, then there's an issue in the secondary circuit which overloaded it.
I once had the secondary of a new transformer blow right away, so I installed an in-line fuse with the transformer's secondary. From there it was a troubleshooting technique I call “trial by blowing the fuse” (which is necessary on rare occasions). I disconnected all of the plugs to the control board, reconnected power to the control board and …ZZZ! The fuse blew. So, the control board was shorted internally.
BTW: My ohmmeter did NOT detect the short, so ohming stuff out with it didn't work in that scenario. The fuse became my troubleshooting tool to detect the short.
I think you might be barking up the right tree. It is the secondary winding that is not working correctly. I popped the cover off the transformer, and there is a tiny inline fuse that was blown. I'm going to try swapping out the transformer and new control boards all the same time today, and see if that fixes the issue.
Replaced the transformer and control board and was able to get the machine to power on. Reprogrammed the control board to work with the LxiH instead of the AM15 it has been set for, it fired up, started the fill cycle, then crashed and the heaters continued to fire until the wash water boiled. All in all, a step in the right direction, but not a resolution. Ordered a brand new control board instead of the spare, hopefully that resolves the issue.