I didn't post much about this because I don't suggest people try it.
I took the cover off (drill out four rivets), defying the warning not to, and twiddled the voltage pot. I overdid it or whatever, managing to set fire to the in-rush current thermister, which was exiting. I was able to replace that with a new thermister and by a miracle, the converter worked again. I gave myself a circuit board repair tech certificate.
I wanted to go higher than 14.6 but decided maybe it would be safer to leave it at that and not have another fire :)
So far so good, used it several times now. It replaces three Vector 35 ampers saving me the bother of playing with those. ( I still have them though, in case my repair job eventually goes up in smoke---I am kind of nervous about that still. :( ) I hope to eventually get over that!