C. Check the switch transformer for sounding. If the transformer sounds, remove the load on the power
supplies of 30V DC and 12V DG. If still without 30V DC output after removal, then the switch power is
defective. If with 30V DC output, the load is short – circuited but the switch power is good. Then check
the secondary load circuit.
D. Check D401, D402, C408 and D403 for PWM (66KHz) output.
E. Check VD405 and VD406 for breakdown.
②
With voltage output (much different from 30V DC)from two ends of the capacitor C405 (the indicator
lights).
A. Remove the power load.
B. If without 30V DC output but with stable voltage, check R401 and R403.
8.2.2.2
Power supply is OK.
①
Check the power supply connected to D300 (MCU) for normality.
②
Check whether the toggle switch (XS310) buzzes when the switch inputs.
③
The sensor gives an alarm.
④
Over-current alarms (check the switch power for correct installation and check the compressor current
detector.)
8.2.3 The indoor fan does not run.
Check the fan for being in protection.
8.2.4 the louver motor does not run or runs improperly.
8.2.4.1
Check the power supply 12V.
8.2.4.2
Check the motor for being in protection.
8.2.4.3
Check the PCB (XS301 and D300) for welding loosely or welding jointly.
8.2.4.4
Replace the step motor.
8.2.5 Sensor alarm, units stop.
8.2.5.1
Check the 5V power supply.
8.2.5.2
Check PCBs for welding loosely.
8.2.5.3
Check the sensor for being damaged.
8.2.6 The outdoor compressor, fan and four-way valve do not run.
8.2.6.1
Check input and output of relay K301 for fan. Check input and output of relay K302 for four-way
valve.
8.2.6.2
Check input and output of relay K303 for compressor.
8.2.6.3
Check 12V power supply.
8.2.6.4
Check
the connection wiring.
8.2.6.5
Check the relay and start - up capacitor.
8.2.6.6
Check whether the compressor, fan and four – way valve are in good condition.
8.2.7 No signal, indicators does not light.
8.2.7.1
Check the remote control for being damaged or the batteries for being exhausted.
8.2.7.2
check for obstacles between the unit and remote controller.
8.2.7.3
Check C305 on the indicator and 5V power supply.
