When The Freezer Fan Does Not Operate - Samsung RL44Q Series Service Manual

TROUBLESHOOTING

4-2-2. When the Freezer Fan does not operate

- A BLDC Fan Motor is applied to this refrigerator and it runs on DC 8~12V.
- The F-Fan motor runs together with the compressor.
☞ Self-Diagnosis Error Display
F FAN ERROR
<Note>
Pulse signals being generated when the motor
is rotating are to be input to CN72 #3 (F).
These will be input to MICOM and when there
are no input signals with the motor rotating, the
fan will be turned off and then be turned on in 10
seconds.
If there are still no input signals, it keeps trying
the above 4 times. And, if it still fails, it runs the
motor in 10 minutes. It is implemented to
prevent the motor
from being overloaded due to restrictions by
foreign substances such as ice built up around
the motor.
It is pulse signal. So, the voltage keeps changing.
But, when it is measured with the Multi-Meter, it
reads about 2~3V.
Start
Compressor is Off.
YES
It reads DC8~12
between MAIN PCB
GND and CN72 #2.
NO
Apply power in 5 minutes
after turning the motor off.
(To prevent the compressor
from being overloaded)
It repeats DC8~12V, and
DC 2V or lower between
MAIN PCB GND and CN72
PIN #2.
YES
◆ Possible Causes
➀ Defective FAN-MOTOR
➁ Contact problem at the terminal (MAIN PCB CONNECTOR -TERMINAL
(CN72, ➀, ➁, ➃), Contact problem at Freezer Fan Motor Connector,
Defective Motor Wire)
➂ Check the motor rotating pulse input upon Fan Motor operation.
(Refer to Fan-Motor Circuit in this manual)
72
NO
Run Forced Operation
YES
FAN operates.
Upon the initial power on,
the compressor and the
F Fan operate for 5 minutes
regardless of the conditions.
(But, when the Freezer temp
is lower than 5°C, it will be
regarded as an instant power
failure, starting in 5 minutes.)
NO
Replace MAIN PCB
☞ How to measure voltage for the F-Fan Motor
- The voltage between the Common PCB Ground and the FFan
CN75-"3" (Orange) is DC7~12V.
- When the measurement is different, it needs additional checking.
1) F-Fan
NO
Common PCB Ground
REG1-Heat sink