Microwave stops heating shortly after start and displays E02 on the control panel.

Safety first: Unplug the microwave. Internal components can store high voltage; do not touch the high-voltage section (capacitor, transformer, magnetron terminals) unless properly trained.

Basic user checks:

• 1. Check ventilation: Ensure the microwave has adequate clearance on all sides per the Sharp manual (typically several centimeters). Remove any items blocking the side, rear, or top vents. Clean dust and grease from external vents with a soft brush or vacuum.
• 2. Inspect cooling fan operation: With the unit reassembled and plugged in, start the microwave with a cup of water and listen at the rear/side for the cooling fan. You should hear a steady fan noise. If the fan is silent or intermittent, the fan motor or its wiring may be faulty.
• 3. Internal thermal cut-out (TCO) check (advanced): Unplug the unit and remove the cabinet. Locate the thermal cut-out mounted on or near the magnetron. Using a multimeter, test for continuity. If open (no continuity) and it is a non-resettable type, it must be replaced with the exact Sharp-specified part.
• 4. Clean internal air path (if accessible): Carefully remove dust buildup around the fan and air channels without disturbing high-voltage wiring.

When to call a technician: If the TCO is open, the fan is not running, or the magnetron appears heat-damaged or discolored, professional service is recommended. Magnetron and high-voltage repairs should only be performed by qualified technicians.