Microwave display shows E04 and cooking cannot be started; sometimes appears after a power surge.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety: Unplug the microwave before touching any internal wiring. Avoid removing the outer cabinet unless you are qualified; internal components can be hazardous.
Reset and basic checks:
- Unplug the microwave for at least 5 minutes to allow the control electronics to fully discharge.
- Plug back in and set the clock if required, then attempt a simple heating cycle.
- If E04 appears immediately, try a different wall outlet (not an extension lead) to rule out supply issues.
Control panel inspection (low risk):
- Check that the control panel and display are firmly seated and not loose in the fascia.
- Wipe the touch panel with a slightly damp, non-abrasive cloth to remove any moisture or residue that might cause false key presses. Dry thoroughly.
Advanced checks (technician recommended):
- Inspect and reseat the ribbon cable between the touch panel/display and the main control PCB.
- Check for visible burn marks or damaged components on the control board.
- Reprogram or replace the control PCB if EEPROM or microcontroller failure is confirmed.
If E04 persists after a full power reset and cleaning, the control PCB or touch module will likely need replacement by a professional.