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

Safety first: Unplug the microwave from the mains before any disassembly. High-voltage components inside a microwave can retain a dangerous charge even when unplugged. Do not touch the capacitor, magnetron, or HV wiring. If you need to remove the outer cabinet, this job is best left to a qualified technician.

Basic checks (no cabinet removal):

• Open and close the door firmly several times. Check that the door sits evenly and that the latch hooks engage smoothly.
• Inspect the door latch area for broken plastic hooks, bent metal, or debris preventing full closure.
• Check that the door is not sagging on its hinges; gently lift the door to see if there is excessive play.
• Unplug the unit for 5–10 minutes to reset the control board, then plug back in and test.

Intermediate checks (door switch area – risk of exposure to HV parts):

• If you are experienced and local regulations allow, remove the control panel/inner trim to access the door switches mounted on the door latch bracket.
• With the unit unplugged, use a multimeter to test each door switch (commonly marked as primary, secondary, and monitor) for correct continuity when the door is opened/closed.
• Replace any switch that does not change state correctly or shows intermittent readings. Use OEM SMEG-compatible door switches.
• Inspect the wiring harness and connectors to the switches for heat damage or loose terminals and reseat as needed.

When to call a technician: If E01 persists after confirming the door closes correctly and replacing faulty switches, the issue may be with the control PCB safety circuit. Control board diagnosis and replacement should be done by a qualified technician due to the proximity of high-voltage components.