Unit powers on but compressor never starts; only the fan runs and air is not cold.

Safety first: Unplug the unit. Capacitors can store dangerous charge; discharge properly before handling.

Steps to diagnose compressor non-start:

• 1. Listen for compressor: When switching to COOL, you should hear a distinct click and a low hum from the compressor. If you hear nothing, suspect the relay or control board.
• 2. Check voltage: Ensure the unit is plugged directly into a dedicated outlet with proper voltage. Avoid extension cords.
• 3. Inspect run capacitor: Access the electrical compartment and locate the capacitor. If it is bulged, leaking, or rusted, replace it with the exact µF and voltage rating specified for your Insignia model.
• 4. Check wiring to compressor: Confirm all spade connectors are tight on the compressor terminals and not burned.
• 5. Advanced tests: Measuring compressor winding resistance and start current should be done by a technician. If the compressor is open or locked, replacement of the sealed system is required.