Microwave stops mid-cycle and shows E4; may occur more often on grill or convection modes (if equipped).

Safety warning: Disconnect power before opening the cabinet. Internal components can be hazardous.

Steps:

• 1. Allow cooling: Leave the door open and let the microwave cool for at least 30 minutes. Try a short cook cycle. If E4 appears only after extended use, overheating is likely.
• 2. Check installation clearance: Ensure the microwave is not built into a tight cabinet unless it is a built-in model designed for that purpose. Follow Morphy Richards spacing guidelines.
• 3. Inspect vents: Clean dust and grease from the top and rear vents. For grill/convection models, clean the grill element area and fan cover.
• 4. Access thermal cut-out: With the unit unplugged and cover removed, locate the cavity thermal cut-out (often mounted on the top of the cavity or near the grill element). Inspect for discoloration or loose mounting.
• 5. Test continuity: Use a multimeter to check the thermal cut-out. Replace it if it reads open circuit and does not reset when cool.
• 6. Check convection fan (if present): Spin the convection fan by hand and check for free movement. If stiff, noisy, or not running during convection/grill modes, replace the convection fan motor.

After repair: Reassemble, plug in, and test on a low-power setting first, then grill or convection. If E4 persists, the control PCB temperature monitoring circuit may be defective.