Bosch Primary Interlock / Power Feed Interruption

Microwave cavity light and fan work, but the turntable and heating do not start when pressing Start.

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

Failed primary door switch, Faulty control board relay for HV circuit, Loose wiring to high-voltage transformer, Safety interlock misalignment

How to Fix / Troubleshooting

Safety: Unplug the microwave before inspection.

Check door closure: Ensure the door is fully closed and latching properly.
Reset power: Unplug for 5 minutes, then reconnect and test again.

If the symptom persists: The primary interlock switch or HV relay is likely faulty. These are internal safety components and must be serviced by a Bosch technician.

Repair Difficulty

Hard 4/5

Required Part

Primary Door Switch

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