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

Safety first: Unplug the microwave from the wall outlet before any disassembly. High-voltage components inside a microwave can retain a dangerous charge even when unplugged. Do not touch the high-voltage capacitor or magnetron area unless you are trained and properly equipped.

Step-by-step checks:

• 1. Inspect the door and latches: Check that the door closes evenly and fully. Look for cracked or bent latch hooks on the door and damaged latch openings on the cabinet. If the door feels loose or misaligned, do not force it; the interlock switches may not be engaging.
• 2. Test door switches (interlock switches): Remove the outer cabinet (usually several screws at the back and sides). Locate the door interlock switch cluster near the door latch assembly. There are typically 2–3 microswitches. With the unit unplugged, use a multimeter in continuity mode to test each switch while pressing and releasing the actuator. Replace any switch that does not change state (open/close) correctly.
• 3. Check wiring harness and connectors: Inspect the wiring harness from the door switches to the control board for loose connectors, burnt terminals, or broken wires. Reseat any loose connectors firmly.
• 4. Reassemble and test: Refit the cabinet, ensuring no wires are pinched. Plug the microwave back in and test with a cup of water. If E01 persists after switch replacement, the control board may be misreading the interlock circuit and should be evaluated by a qualified technician.

When to stop: If you are not comfortable working around high-voltage appliances or cannot access the switches safely, stop and contact a Sharp-authorized service center.