Timer counts down but heater and fan never turn on; only the display is active.

Safety first: Unplug the air fryer before opening the housing. Relays switch mains voltage.

Steps to troubleshoot no-output condition:

• 1. Listen for relay clicks: Start a cycle and listen closely. Normally you should hear faint clicks as relays engage. If none are heard, suspect the board.
• 2. Inspect main control board: Remove the cover and locate the relays (small rectangular components). Check for burn marks or cracked solder joints underneath.
• 3. Resolder joints (advanced): If you see cracked solder around relay pins and are skilled with soldering, reflow the joints. Otherwise, replace the board.
• 4. Replace main control board: If relays are not energizing or are burned, install a new Insignia main control board.

Warning: Do not attempt to manually short relay contacts; this is dangerous and can damage the appliance.