Display shows E6 and unit will not operate in cooling or heating mode.

Safety: Unplug the air conditioner before removing the control panel or covers.

• Access control area: Remove the front bezel or top cover to expose the user interface (display board) and the main control PCB.
• Inspect harness: Locate the multi‑wire ribbon or harness that connects the display board to the main board. Check for pinched, cut, or burnt wires.
• Reseat connectors: Unplug the harness at both ends and plug it back in firmly. Ensure it is fully seated and latched.
• Check for corrosion: Look for green/white corrosion on connector pins. Light corrosion can sometimes be cleaned with contact cleaner and a soft brush; heavily corroded connectors or boards should be replaced.
• Visual board inspection: Examine both PCBs for burnt components, cracked solder joints, or water damage (from condensation or spills).
• Test operation: Reassemble enough to safely power the unit and test. If E6 clears, the issue was likely a loose connection.
• Board replacement: If E6 persists, replace the display/control panel board first (often the more common failure). If that does not resolve it, the main control PCB will likely need replacement.