Samsung Electronics5-85-3-3 Detailed ProcedureTroubleshootingNo.123456MalfunctionPull out the power plug from theAC terminal and confirm the fuseon the PCB assemblyTurn the power on.If lamp blinks trouble is notrelated to the items 1 through 4on the right.Set operating mode when RMCswitch pushed.Except for [FAN]mode and[TIMER] mode.Set operating mode when RMCswitch pushed.1. COOL mode2. Fan speed [AUTO]3. Set temperature lowerthan room temperature4. Continuously operation.Set operating mode whenRMC switch pushed.1. HEAT mode2. Fan speed [AUTO]3. Set temperature higher thanroom temperature4. Continuously operationSet operating mode whenRMC switch pushed.1. [FAN] mode2. Fan speed [Hi]3. Continuously operationChecking point (symptoms)1. Is the broken?Voltage check1. AC voltage at both end of transformer Primary?198 - 264V~2. AC voltage at both end of transformer secondary?14- 18Vac3. DC voltage at OUT and GND of IC01(KA7812)? 12VDC4. DC voltage at OUT and GND of IC02? 5VDC5. DC voltage at Q201 Base and GND change?squarewaveVoltage check1. Voltage of relay (RY71) coil Voltage atpin#10, pin#7 of IC07 : 12VDC2. Voltage at Terminal Tap (TB71 or 72) andRY71 Terminal N0 4 . 198- 264V~1. Compressor does not operate.1. Compressor does not operate1. Voltage at 3 5 both ends of CN73 :above 180V~2. Indoor unit fan motor does not operate.Causes1. Voltage over2. Indoor unit fan motor short-circuit.1. Irregular power code or power fuse,or poor wiring.2. Transformer is faulty.3. Power circuit is faulty.4. Power circuit is faulty.5. Q201 is faulty.D101~D104 (IN4007)1. Relay(RY 71) coil is open.IC6(ULN2003) is faulty.2. Relay(RY 71) contactor is faulty.1. Temperature of Heat exchangeis lower.2. PCB is faulty.3. Room sensor or Heat exchangertemperature sensor is faulty1. Temperature of Heat exchange ishigher.2. PCB is faulty.3. Room sensor or Heat exchangertemperature sensor is faulty1. Indoor unit fan motor is faulty.2. Poor connection of indoor fan motorand connector of RPM sensing (CN43)