Why Your LG Aircon Light Blinks After a Power Trip: Step-by-Step Guide

Grid surges, lightning storms, or household circuit breaker trips in Singapore can disrupt electronic control boards. When electrical supply is restored, LG Dual Inverter air conditioners often exhibit a blinking power LED or display a **CH** code, refusing to initiate cooling. This blinking state is a protective protocol programmed into LG microprocessors to safeguard delicate inverter power electronics from unstable voltage. ## Why LG Aircons Blink Following Electrical Disruptions Sudden power interruptions trigger several protective mechanisms on LG control boards: * **EEPROM Board Lockout:** Voltage drops cause the indoor and outdoor PCB memory chips to register a power anomaly, locking out compressor startup until an isolation reset is performed. * **Inter-Unit Communication Delay (Code CH05):** Following power restoration, the outdoor inverter board may take longer to initialize than the indoor PCB, causing a temporary communication signal mismatch. * **Surge Protection Fuse Activation:** Severe high-voltage spikes can trip MOV surge arrestors or blow main glass fuses on the outdoor board to protect inverter IGBT modules. * **Compressor Restart Safeguard:** LG systems feature an automated 3-minute compressor restart delay after power restoration to allow system pressures to stabilize. Explore why [aircon circuit breaker power tripping occurs](/blog/aircon-electrical-power-tripping-breaker-solutions-singapore) and how electrical safety devices protect your home. ## Executing a Safe LG Power Isolation Reset Before calling for an engineering inspection, homeowners can execute a safe power reset: 1. Turn off the aircon using the LG remote controller. 2. Locate the main rotary power isolator switch near the outdoor unit or switch off the aircon circuit breaker on your main electrical board. 3. Keep the switch in the **OFF** position for at least 10 to 15 minutes to allow all PCB capacitors to discharge completely. 4. Switch the isolator back **ON** and wait 3 minutes for board initialization. 5. Turn on the unit with the remote controller and select cool mode. If the LG blinking light or CH code resumes immediately, an underlying electrical parameter fault is present that requires a physical site check. Residents in [Clementi](/locations/clementi) or [Queenstown](/locations/queenstown) can rely on our team for professional diagnostic support. ## Professional Diagnostic & Repair Solutions When power trip blinking persists, a technician conducts a physical inspection of isolator wiring, terminal tightness, and PCB fuses. Depending on site findings, necessary repairs may involve replacing blown fuses, rectifying loose wiring terminals, or servicing inverter module components under strict safety protocols. ## Frequently Asked Questions (AEO/SEO Snippet) ### Q: Why is my LG aircon showing CH05 after a power outage? **A:** Code CH05 indicates a communication signal failure between indoor and outdoor boards following a power outage. A 15-minute power isolator reset usually clears temporary signal holds. ### Q: Can a power surge burn my LG inverter board? **A:** Severe lightning surges can damage PCB varistors or fuses. If the unit remains unresponsive after a power reset, a technician should inspect the board physically. ### Q: How long should I wait before turning my LG aircon back on after a blackout? **A:** Wait at least 10 to 15 minutes after power is fully restored to allow grid voltage to stabilize before turning the unit back on.