Microwave will not start; display shows E01 immediately after pressing START.

Safety first: Unplug the microwave from the wall outlet before any inspection. Microwaves contain high-voltage components that can retain a charge even when unplugged. Do not touch internal high-voltage parts (capacitor, magnetron, transformer). If you need to remove the outer cover, this should be done only by a qualified technician.

Step-by-step checks (user-level):

• 1. Inspect the door: Open and close the door firmly several times. Check that it closes evenly and that the latch hooks engage smoothly. Look for cracked or loose plastic around the latch area.
• 2. Check for obstructions: Ensure no food debris or warped door seals are preventing full closure. Wipe the door frame and latch area with a damp cloth.
• 3. Test door actuation: With the door open, gently press on the latch hooks (without forcing them) and listen for distinct clicks from the internal switches as you open/close the door. Weak or no clicking suggests a faulty switch or misalignment.
• 4. Power reset: Unplug the unit for 5–10 minutes, then plug back in and test again. If E01 returns immediately, the door safety circuit is likely at fault.

Technician-level checks (do not attempt if you are not trained):

• Remove the outer cabinet and test the primary and secondary door interlock switches with a multimeter for continuity when the door is closed.
• Inspect the door switch wiring harness and connectors for heat damage or loose terminals.
• Replace any defective door interlock switch or damaged latch components with Breville-compatible parts.

If the error persists after confirming the door closes properly, contact a qualified appliance technician or Breville service center. Do not bypass or short any safety switches.