Samsung Air Conditioner Error Code YEL_FLICKER_RED_ON

The YEL_FLICKER_RED_ON error code on a Samsung air conditioner indicates an OLP (Over Load Protector) sensor fault, specifically an open circuit or short circuit condition detected at the OLP temperature sensor. The OLP sensor monitors the compressor or refrigerant circuit temperature to prevent the system from operating under dangerously high thermal loads. When the control board reads a signal from this sensor that falls outside the expected resistance range, either because the circuit is completely open or has shorted to ground or another conductor, it triggers this fault and halts normal operation to protect the system.

The primary diagnostic entry point is the OLP temperature sensor connector located at CN52, pins 1 and 2. A technician should begin by inspecting the connector for corrosion, bent pins, or loose seating, then proceed to measure the sensor's resistance across those two pins. A properly functioning NTC-type temperature sensor will show a predictable resistance value corresponding to the ambient or refrigerant temperature at the sensor location. An open circuit will read infinite resistance (OL on a multimeter), while a short will read near zero ohms. Either reading confirms sensor or wiring failure.

Common contributing factors include physical damage to the sensor wiring harness, moisture intrusion at the connector causing corrosion, thermal degradation of the sensor element from prolonged high-temperature exposure, or a manufacturing defect in the sensor itself. Because this fault directly involves compressor protection circuitry, the unit should not be operated or bypassed until the root cause is identified and corrected.