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

Safety first: Unplug the microwave from the wall outlet before any disassembly. Microwaves contain a high-voltage capacitor that can retain a dangerous charge even when unplugged. Do not touch internal high-voltage components (capacitor, transformer, magnetron). If you are not experienced, contact a qualified technician.

Step-by-step checks:

• 1. Verify door closure: Make sure the door closes fully and evenly. Check for food debris or warped door seals that may prevent the latch hooks from engaging the switches.
• 2. Inspect door latch hooks: With the unit unplugged, open the door and inspect the plastic latch hooks on the door. If they are cracked, loose, or bent, the switches may not actuate correctly.
• 3. Test door switches (interlocks): Remove the outer cabinet (usually screws at the back and sides). Locate the door switch cluster near the latch assembly. Using a multimeter set to continuity, test each switch while pressing the actuator. Replace any switch that does not change state (open to closed or vice versa).
• 4. Check switch mounting bracket: Ensure the metal or plastic bracket holding the switches is not bent or broken. A misaligned bracket can prevent proper switch operation.
• 5. Reassemble and test: Reinstall the cabinet, plug the microwave back in, and test operation. If E01 persists, discontinue use and seek professional service.