Blomberg Start Circuit / Interlock Inhibit

Microwave will not start at all; display is on but pressing Start does nothing and no error code appears.

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

Faulty Start button on keypad,Defective door interlock switch,Blown internal line fuse,Failed control board relay

How to Fix / Troubleshooting

Safety: Unplug the microwave before any internal inspection.

User checks:

1. Verify door closure: Ensure the door is fully closed and latched. Try gently lifting or pressing on the door while pressing Start. If it starts intermittently, the door switches or latch are suspect.
2. Test other buttons: Check if other keys respond (clock set, timer). If only Start is unresponsive, the keypad may be faulty.
3. Power reset: Unplug for 5–10 minutes and try again.

Advanced checks:

4. Door switches: Access and test the door interlock switches with a multimeter. Replace any that fail continuity tests.
5. Line fuse and relay: Check the internal fuse and main power relay on the control board. Replace with identical-rated parts if failed.

Repair Difficulty

Hard 4/5

Required Part

Door Interlock Switch Kit

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