When Defrost Does Not Operate - Samsung RS2511 Series Service Manual

Diagnostics

8-5) When Defrost does not operate

Pre-Check
1. With a shorted-out Defrost Sensor, the fridge operates normally excepting Defrost(The fault can be picked up
with self-diagnosis, POWER ON/OFF).
2. There will be Heating trouble with a shorted-out Temp FUSE, which contributes to Defrost by natural Temp
increase resulting in a Temp Control problem stemmed from the increased COMP OFF time.
3. When Defrost Sensor is faulty as OPEN, Heating will not be terminated, and COMP will remain off following
the Temp FUSE short-off.(The fault can be picked up with self-diagnosis, POWER ON/OFF)
YES
A
COMMON RELAY RY71
Defrost Heater RY72
RELAY CHECK
REFERANCE
Start
Dose Defrost work upon
Forced Defrost KEY pushed?
YES
NO
Is power supplied to
Defrost Heater?
NO
Is MICOM #30
"HIGH"(5V)?
YES
Is output #16 of IC3
low?
YES
Is Defrost Heater
Relay (RY76) normal?
YES
Is contact of Connector
N71(browwn) normal?
YES
Is Bimetal in EVAP.
normal?
YES
Is Defrost Heater
shorted out?
NO
Check wire assembly
40
NO
Is concerned Defrost Sensor
Temp higher than 12 °C?
YES
Maintain Forced Operation for a
certain time
NO
Check soldering, Change PCB
NO
Check IC3 / Change PCB
NO
Check RELAY / Change PCB
NO
Check contact of Connector CN71
again
NO
Change Bimetal
YES
Change EVAP. ASS'Y