Samsung RH29H9000SR Service Manual page 70

TROUBLESHOOTING
4-2-6. When Fan does not operate
- This model has BLDC FAN motor. BLDC motor is driven by DC7~12V
- F-Fan motor usually runs together with the Compressor. Once the door is open and closed at high
ambient temperature, F-Fan motor put off its operation for one minute. Therefore, you are advised
not to take it as an error.
- When fridge door is open, the F-Fan motor stops.
For C-FAN
The voltage between GND in Main PBA
For C-FAN
GND and CN74 #2 repeats the change from
Note
Pulse signal(FG) generated from the Fan motor rotation is transmitted through CN74 #9(F), #11(C)
Micom senses these signal.
If Micom senses no signal, Micom make Fan Motor stop for 10 sec and try to operate it again.
Micom keeps doing the same procedure 4 times until Micom receive the signal.
If it still fails, MICOM stop trying for 10 minutes.
This procedure prevents the motor from overload when foreign substances such as ice built
up around the motor restrict motor rotation.
and CN74 #2 is 8-12Vdc
NO
Reading with Door closed.
-.OPEN 5V, CLOSE 0V
The voltage between
7-12VDC to lower than 2VDC.
YES
70
Start
NO
COMP is on?
YES
For F-Fan
YES
The voltage
between GND in Main PBA and CN74
#4 is 8-12 VDC
NO
NO
Freezer/Fridge/Home
Bar Door S/W is closed.
YES
Plug in again after 5
minutes from the power off.
For F-FAN
NO
The voltage between
GND and CN74 #4 repeats the change from
7-12VDC to lower than 2VDC.
YES
◆ Possible Causes
1. Defective FAN-MOTOR
2. Contact problem at the terminal
3. FG signal error (Refer to Fan-Motor circuit in this manual)
☞ Checking method of C-Fan motor voltage
-. Read the voltage between MAIN PBA GND and CN74 #2
-. If it has 8~12 voltage, It's normal.
(Same method is applied to other Fan Motor)
Run Forced Operation
FAN operates normally.
Check after closing the
Door. When there is Door
alarming, repair the Door
S/W connector.
Upon the initial power on,
Comp and F/C-Fan operate
for 5 minutes regardless of
the conditions.
Replace MAIN PBA
CN74