Samsung RB1855SW - Load Circuit Testing; Sensor Resistance Checks

58
Subordinate
R Defrost heater
F Defrost heater
Comp
Comp-circulation fan
R-Circulation fan
F-Circulation fan
R-Lamp
F-Lamp
Evaluation of mea-
surement result
Measurement
terminal
CN70 ⑤ - ①
CN70 ⑦ - ①
CN70 ⑨ - ①
CN70 ③ - CN71 ①
CN71
⑦ - ①
CN71 ⑤ - ①
CN71 ⑨ - ①
CN71 ③ - ①
1. Measure resistance between the terminals and
check for malfunctioning of a load and wire
connection.
1. R sensor measures resistance of CN30
between ②~⑤.
2. Freezer sensor measures resistance of CN30
between ①~⑤.
3. R-defrost sensor measures resistance of CN30 between ④~⑤.
4. F-defrost sensor measures resistance CN30 between ③~⑤.
5. The measured value above is compared to the sensor specification and the temperature table in
speciication found in the manual.
* Unplug the power cord and disconnect the
connector from the main PCB CN70, 71 and
measure the following:
Category of contacts
3 contacts
2 contacts
Voltage between both of
the contacts
C:NO → SHORT
C:NC → OPEN
C:NO → OPEN
C:NC → SHORT
SHORT
OPEN
Voltage between both
of the coil terminals
DC 12V
(OPERATION)
DC 0V
(NO OPERATION)
DC 12V (OPERATION)
DC 0V(NO OPERATION)
1. Judge if it operates or not by measuring the
voltage between both of the relay coil terminals.
2.
Judge Open/Short by measuring both of the contacts.
3. When it operates like the above, it is OK. If not,
replace the relevant relay.
* Remove the housing connected with the Main
PCB CN70 & 71,load connection terminals,
and then measure the following.
* Disconnect the connector from the main PCB
CN30.
* Resistance will be lowered while the
temperature rises due to a NTC type sensor.
Ref. 4) Check sensors
Ref. 3) Check a load