Howard and Jessie got the SCRs replaced. After we started the power supply we found that one bank of SCRs was not firing. This was already suspected. After a lot of poking around, there is not too much to say. A fair amount of just plain confusing data was accumulated. A different firing circuit looked like all the SCRs are firing, but the AC current draw seems to show it is not so. A little time to mull over what has been seen might help.