The controller board on my parents' Whirlpool wall oven went bad a couple weeks ago. Replacement part is NLA (no longer available) due to trouble with the supplier from which Whirlpool sourced the board. Unfortunately this is not an uncommon occurrence. The oven is only 5 years old (no longer under warranty of course), but the model in question has been in production for a long time, introduced in 1995.

The solution is to have the board repaired. Two electronics repair services are available that handle appliance boards (there may be more).

CoreCentric Solutions

FixYourBoard.com

CoreCentric Solutions was recommended by Whirlpool. However, I used FixYourBoard due to a better warranty on the work. Turnaround time was just one day, although I suppose that depends on how much work they have in the queue. Total time including transit there and back via UPS Ground was Tue > Fri. (UPS Ground can effectively be overnight within the state in some instances).

Perhaps this info will be helpful to others in the same situation.