Midea MCD-18HRFN1-QRC4 Service Manual page 127

the value is not 5V, change the PCB. Otherwise, go to step 3.
3) Rotate the fan by hand, measure the voltage of pin1-5, pin 2-5 and pin 3-5 in feedback signal connector.
If any voltage is not positive voltage fluctuation, the fan motor must has problems and need to be
replaced.
Index2:
1. Indoor DC fan motor(control chip is inside fan motor)
Power on and when the unit is in standby, measure the voltage of pin1-pin3, pin4-pin3 in fan motor
connector. If the value of the voltage is not in the range showing in below table, the PCB must have
problems and need to be replaced.
For other models:
DC motor voltage input and output
NO. Color
1 Red
2 ---
3 Black
4 White
5 Yellow
6 Blue
For console:
DC motor voltage input and output
NO. Color
1 Red
2 ---
3 White
4 Blue
5 Yellow
6 Black
Electrical Control System
Signal Voltage
Vs/Vm 192V~380V
--- ---
GND 0V
Vcc 13.5-16.5V
Vsp 0~6.5V
FG 15V
4
1
Signal Voltage
V 310V
DC
--- ---
Vcc 15V
FG 15V
Vsp 0-7.5V
GND 0V
5
6
3
2
Troubleshooting
133