Microwave does not heat and displays E3 within a few seconds of starting.

Safety warning: Always unplug the microwave before removing the cabinet. The high-voltage capacitor can retain a lethal charge; only trained persons should work near the magnetron and HV circuit.

Basic checks:

• 1. Check ventilation: Ensure the microwave has adequate clearance on all sides as specified in the Morphy Richards manual. Remove any obstructions from the rear and side vents.
• 2. Clean filters and vents: If your model has a removable grease filter or charcoal filter (for combination/grill models), remove and clean or replace it. Use a soft brush or vacuum to clear dust from the intake and exhaust vents.
• 3. Listen for the cooling fan: Start a short cook cycle with a cup of water. Listen carefully for the internal cooling fan. If you do not hear the fan running but the turntable moves, the fan motor may have failed.
• 4. Inspect thermal cut-outs (for trained persons): With the unit unplugged and cover removed, locate the magnetron thermal cut-out (small round thermostat clipped to the magnetron or waveguide). Check for signs of overheating or discoloration.
• 5. Test continuity: Using a multimeter, test the thermal cut-out for continuity. An open reading indicates it has tripped or failed. Some are non-resettable and must be replaced.
• 6. Check fan motor: Spin the fan blades by hand (from the rear or inside, depending on model). If stiff or seized, replace the cooling fan motor. Verify its wiring and connector at the control PCB.
• 7. Replace faulty parts: Install a new Morphy Richards-compatible magnetron thermal cut-out or fan motor as needed. Ensure all screws and clips are secure.

Final step: Reassemble the cabinet, plug in, and test heating with a cup of water for 1–2 minutes. If E3 returns, the magnetron itself or the control PCB may be faulty and should be evaluated by a professional technician.