A model number would be helpful.
Model Number Locator
You may have a problem with the 240 volts going to the unit.
It is required to heat all the elements on the unit.
The lights, control/clock all run of of half the line (120 volts)
Try flipping the breaker off/on slowly a couple times, sometimes you can loose half the line without actually tripping the breaker.
If this does nothing, check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
Check the power at the terminal strip.
Be careful as 240 volts is lethal !!!