Microwave runs but stops with E04 error; food remains cold.
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
Critical safety warning: The high-voltage section of a microwave (transformer, capacitor, diode, magnetron) can be lethal. The capacitor can store a dangerous charge even when unplugged. Only trained technicians should work on these components.
- Step 1 – Basic checks only: Unplug the microwave. Do not remove internal covers beyond the outer cabinet if you are not qualified.
- Step 2 – Confirm symptom: Place a cup of water inside and run for 1–2 minutes. If the turntable and light work but water stays cold and E04 appears, the high-voltage system is likely at fault.
- Step 3 – Visual inspection: With the outer cabinet removed, visually inspect for burnt smells, charred wiring, or obvious damage around the magnetron and transformer. Do not touch or probe the high-voltage parts.
- Step 4 – Professional service: Due to the risk, arrange service with a qualified Severin service center. They will test the magnetron, HV diode, capacitor, and transformer with proper discharge and safety procedures.
If the unit is older and the magnetron is confirmed faulty, compare the cost of magnetron replacement versus a new microwave.