Microwaves weren't the first cook-it-fast devices. Convection ovens have been around many years. If yours doesn't work, fix it!
A convection oven is a standard oven with a circulation fan to bake and roast food. (click to enlarge)
A convection oven is an appliance for baking and roasting food. It works like a conventional oven but includes a fan that circulates hot air around the food allowing it to cook faster than in a conventional oven and more evenly than in a microwave. Hybrid ovens combine the advantages of both a convection oven and a microwave oven in one unit.
Convection ovens use a motor-driven circulating fan that's mounted between the unit's inner and outer housings. A timer controls the fan and the heating element. Additional controls are located inside the front control panel.
To access any of the components you'll need to first disassemble the convection oven.
Disassemble a convection oven:
Unplug the oven. Remove the door, shelves, and all control knobs. Remove screws behind the timer knob and around the edges of the front housing. Lift off the control-panel housing. Disconnect the light before completely removing the housing.
To remove the selector switch, loosen any screws and metal tabs holding the switch to the panel base.
To remove the timer, loosen any screws securing it.
To remove the temperature control, unscrew the locking ring around the temperature control spindle.
Slide the unit's base forward, then lift it over the control panel.
Remove any outer housing screws, then grasp the housing and remove it.
Test and replace internal components as needed, referring to the owner's manual or a parts diagram available from the manufacturer.