63
12-5) When Defrost does not operate
Diagnostics
1. With a shorted-out F or R 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 a F or R 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)
Pre-Check
NO
NO
NO
NO
NO
NO
NO
Dose Defrost
start operating when F or R
Forced Defrost button
pushed?
Is concerned
Defrost Sensor Temp higher
than 12
℃
?
Is power supplied to
Defrost Heater?
A
Are MICOM #21 
"HIGH"(5V)?
R Defrost Heater #21
F Defrost Heater #15
R Defrost Heater IC70 #11
F Defrost Heater IC52 #17
COMMON RELAY K72
R Defrost Heater K71
F Defrost Heater K70
Are IC70 #11 &IC52
#17 "LOW"(0.7V)?
Is Defrost
Heater Relay (K71,K70)
normal?
Is contact of
Connector CN70 normal?
Start
YES
YES
Maintain Forced Operation
for a certain time
PANEL PCB KEY
Press Super Cool and Fridge
at the same time for 5 sec.
Press any button 3 times when
the entire display blinks.
-.Once:Forced Operation
-.Twice:R Defrost
-.3 times:F/R Defrost
-.4 times:Cancel
Change PCB
YES
Check IC70 &IC52 /
Change PCB
YES
Check RELAY /Change PCB
YES
Check contact of Connector
CN70 again
YES
YES
NO
Is Temp FUSE
on EVAP. normal?
Change Temp FUSE
YES
YES
Is Defrost Heater
shorted out?
Change EVAP.ASS'Y
NO
Check wire assembled
status/Chang MAIN PCB ASS’Y