Remote control does not operate the indoor unit; no response to button presses.

Safety first: For any work on the indoor electronics, turn off the breaker first.

• Replace batteries: Install new, high-quality batteries in the remote, ensuring correct polarity.
• Check IR transmission: Point the remote at a smartphone camera and press a button; you should see a flashing light on the camera screen. If not, the remote may be faulty.
• Clear line of sight: Ensure nothing blocks the IR receiver window on the indoor unit and clean it with a soft cloth.
• Test with another remote: If available, test with a compatible Sharp remote. If the unit responds, replace the original remote.
• IR receiver board: If no remote works, the IR receiver/display board or its cable may be faulty. Replace the IR receiver board assembly.