Princess oven displays E11 and the interior light does not work, or the oven will not start because it thinks the door is open.

Safety first: Disconnect power before changing bulbs or accessing switches.

• Replace lamp: Remove the glass cover over the oven lamp, unscrew the bulb, and inspect the filament. Replace with a high-temperature oven bulb of the correct wattage.
• Inspect lamp holder: Check for signs of arcing or burning at the lamp socket. Replace the lamp holder if damaged.
• Test door switch: If the oven still reports door open, test the door switch for continuity when pressed. Replace if faulty.

If lamp and switch are good but E11 remains, the control board input circuit may be damaged and the board should be replaced by a technician.