Samsung RT38 Service Manual page 50

TROUBLESHOOTING
4-2-3. When Defrost does not work (F DEF Heater)
- When there is a trouble in defrosting, select the Self-Diagnosis function before turning off the unit. And,
check if there is any defect in the Defrost Heater. If not, plug out the unit and do the Trouble-Shooting. (Refer
to the Self-Diagnosis function and check the details)
** Heater Resistance Reading Location **
F-DEF : Resistance between CN70 #5 (BRN) ↔
CN77 #3 (ORG) should be ohm ± 10%.
** 0Ω : Short / ∞Ω : Open
(Bimetal / Thermal Fuse / Heater Defect)
** Sensor Resi s tance Readi n g Locati o n **
F-DEF : Between CN30 #4 (RED) ↔ CN76-"1" (BRN)
** 0Ω : Short / ∞Ω : Open
Temp vs. Resistance Table
30℃ 4.22
20℃ 6.05
For more
10℃ 8.87
detail data,
0℃ 13.29 refer to
DATA1. Temp
-10℃ 20.42
Table
-20℃ 32.23
-30℃ 52.41
** Sensor Voltage Reading Location **
F-DEF : Between PCB COMMON Ground
and CN30 #4 (or SEN_2)
** 0V : Short / 5V : Open
After pressing the Power Cool and
the Fridge buttons simultaneously for
6 seconds, push the Fridge button to
enter the Test Mode.
And then, when any one of the buttons
is pressed twice, the Forced Defrost will
start and "3℃, 5℃ and 7℃" LEDs will
light up on the display panel.
Check the related sensors
if they are defective.
Note When the temperature of the F DEF Sensor
goes over 12℃ with the Defrost Heater heating up, it
stops heating and it goes back to Cooling Operation.
SEG Voltage Watt OHM
230 130 406.9
RT29/
RT32
120 130 110.8
230 160 330.6
RT35/
RT38
120 160 90.0
230 120 440.8
RT22/
RT25
120 120 120.0
Start
All Defrost Heaters
are normal?
Yes
Defrost Sensor is
normal? (Check it
with Self-Diagnosis)
Yes
The Sensor
Temperature Value
is lower than 12℃.
Yes
Do Forced Defrost
Power is applied to
F-Defrost Heater.
Yes
No
After heating up for a while, it
goes back to Cooling Operation
Yes
Normal
MAIN PCB
Connection is normal?
Yes
Check Bimetal, Heater Wire
Cut or Wire Contact
Repair Defective Relay or
replace PCB Assy
55
F DEF. ERROR
No
Check Bimetal, Heater
Continuity or Wire Connection
No
Replace the Sensor
No
Forced Operation for a while
No
No
Repair Connector