Jenn Air Wall Oven Faulty after self clean

I have a Jenn-Air double oven that worked great for years. After our new cleaning lady used the self cleaning mode of the top convection oven, (had never been done before) there was an error message and the oven would not work. The message was cleared after turning the power off and on.
Since that time, any time I try to use the oven, the temperature soars past the preset temperature as though it is going in to self-cleaning mode.
The display is bright and the bottom coventional oven works fine.
One repairman, stated that the parts aren’t made for that model anymore however, I have found that can order a control board for $300+.
Ordering the board is non-returnable and means I have spent money I could put towards a new wall oven set if the part does not resolve the problem.
Any suggestions?