Does the oven light work.

The elements use the full 240 but the contol board and oven light need 120 volts so perhaps you have lost Neutral.
I would start by checking the power.

Try flipping the breaker off/on slowly, 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.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
[COLOR="Red"]Be careful as 240 volts is lethal !!![/COLOR]