Jenn Air In Wall Oven - kaput

The oven started a continuous beep, the display is dead. I took the fron panel off and disconnected the wire with a four prong connector to the circuit board behind the display. I kept it off all night. Reconnected it and thought it was working and then the beeping started again. Is it the control panel? Is it the other circuit board (which would be a bear to get to). Any advise or suggestions - please be specific.:eek: