Display works but buttons on the control panel do not respond or respond intermittently.

Safety first: Unplug the unit before removing the control panel.

Steps:

• 1. Try remote: If the remote control operates the unit normally, the issue is likely with the panel buttons, not the main board.
• 2. Inspect panel: Remove the front bezel and examine the keypad area for cracks or signs of liquid damage.
• 3. Reseat ribbon cable: Disconnect and reconnect the ribbon cable between the keypad and display/main board.
• 4. Clean contacts: If accessible, gently clean the keypad contacts with isopropyl alcohol and let dry.
• 5. Replace keypad/display board: If buttons remain unresponsive, replace the display/keypad assembly with a Koldfront-compatible part.