Microwave will not start; display works but pressing START does nothing or beeps and shows E01.

Safety first: Unplug the microwave from the mains. Microwaves contain high-voltage components that can retain charge even when unplugged. Do not touch the high-voltage capacitor or magnetron area unless you are trained.

• Check door closure: Ensure the door closes fully and evenly. Inspect the plastic latch hooks on the door for cracks or deformation.
• Test door switches (basic check): With the unit unplugged, open and close the door while listening for distinct clicks from each switch. If a click is missing or feels mushy, the switch may be faulty.
• Inspect latch and strike: Check the metal or plastic strike plate on the cabinet where the latches engage. If bent or worn, the switches may not actuate correctly.
• When to replace: If the door feels loose, the hooks are cracked, or switches do not click, replace the door switch set / door interlock assembly specific to your Princess model. This usually requires removing the outer cover and should be done by a qualified technician due to high-voltage hazards.