Locate the two house circuit breakers dedicated for the oven and reset both circuit breakers by flipping them both off and on 2-3 times and then see if that will restore power to the oven.
If not, your wall oven uses a thermal fuse that protects the oven from damage in the event of an electrical short or overheating. Check the thermal fuse for continuity. If the fuse is blown, it will kill power to the wall oven.
If the fuse is fine and the control panel has 120 volts supplied, then I suspect the control panel has failed. The display/oven control requires only 120 volts to power up, but the oven elements require 240 volts to heat up.
You can find parts, diagrams, and your owner's manual on Sears PartsDirect: searspartsdirect.com/model/5b7egioudf-001198/whirlpool-wos92ec0as03-electric-wall-oven-parts
This is the fuse: searspartsdirect.com/product/233klshsxx-0022-664/id-w10545255
This is the control panel in stainless steel: searspartsdirect.com/product/4sr5i4kfjf-0022-664/id-w10812332
How to use a multimeter to test electrical parts video: searspartsdirect.com/diy/article/how-to-use-a-multimeter-to-test-electrical-parts-video
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician by calling Sears Home Services at 1-800-4-MY-HOME.
Hope this helps!