Telefunken Control Logic / Relay Activation Failure

Microwave fan runs but the unit does not start heating; START button seems to do nothing.

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

Failed power relay on control board, Faulty START key contact, Broken relay drive transistor, Door not detected as closed

Safety first: Unplug the microwave.

Verify door closure: Ensure the door is fully closed and the door icon (if present) indicates closed.
Test START button: Try other functions; if only START is unresponsive, the keypad may be faulty.
Inspect control board relays: For trained persons, check the power relay solder joints and look for burn marks. Replace the relay or board if defective.
Keypad replacement: If multiple keys fail, replace the membrane keypad.

Hard 4/5

Power Relay on Control Board

Check Price on Amazon

We may earn a commission from links on this page.