Insignia Start Circuit or Door Interlock Logic Fault

Microwave has power and display works, but pressing START does nothing; timer does not count down.

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

Defective START button on keypad,Door not fully closed or misaligned,Failed primary door switch,Faulty control board input circuit

How to Fix / Troubleshooting

Safety Warning: Unplug the microwave before any physical adjustments or internal inspection.

Steps:

Open and firmly close the door; listen for distinct clicks from the latch area.
Check the display for any LOCK or CHILD LOCK icon; disable control lock per the user manual.
Try pressing other keys (e.g., STOP, number keys). If only START is unresponsive, the keypad may be failing.
Unplug the unit for 5 minutes, then plug back in and test again.

Technician-level:

Test the door switches for proper operation with a multimeter.
Check the START key function in keypad diagnostics (if available) or by measuring the keypad matrix.
Replace the control panel/touchpad or main control board as indicated by testing.

Repair Difficulty

Medium 3/5

Required Part

Door Interlock Switch Kit

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