Test Circuit For Sensor - Frigidaire FFBN1721TV0 Technical & Service Manual

Test Circuit for Sensor

The sensor uses NTC (negative temperature coefficient) therm-
istor; the resistance decreases with increasing temperature.
The sensor works according to the following formula:
Sampling voltage / reference voltage = R23 / (RNTC + R23)
where, the reference voltage is 5V and RNTC is the sensor resis-
tance value.
R3
R-Snr
C5
Service Manual - Four-door Refrigerator (FFBN1721TV0 )
Electrical Diagrams
+5V
R23
B5B-XH
CN1
S10B-XH
F-
FD-
SNR
SNR
During the test procedure, first pull out the sensor terminal, place
the multimeter to check resistance between the corresponding
sensor wiring. Verify the resistance values using the table Resis-
tance Values of Sensor (R/T) in the next page to determine
whether the sensor is damaged or not.
CN2
1
RF-SNR
2
+5V
3
4
5
RD-
R-
SNR
SNR
P age 49