Abnormal Diagnosis By Symptom - Samsung AS18A0RCF Service Manual

AS18A9(0)RCF SM_E_15775 3/10/05 7:15 PM
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Troubleshooting (Continued)

2 Abnormal diagnosis by symptom

1. No Power - Initial diagnosis
1. No Power - Initial diagnosis
1) Checklist :
(1) Is input voltage normal? (voltage rating within ±10% range)
(2) Is AC power linked correctly?
(3) Are connections between primary side, secondary side of the power transformer and PCB good?
(4) Is input voltage of DC regulator IC KA7805 (IC02) normal? (11VDC-12.5VDC)
(5) Is output voltage of DC regulator IC KA7805 (IC02) normal? (4.5VDC-5.5VDC)
2) Troubleshooting procedure
YES
Replace PCB Is voltage rating within ±10%
range applied to the between
display
Check linkage between
YES
Check fuse
Does 11~12.5VDC appear
in the input side of the DC
regulator ic ka7805(ic02)?
Replace
PCB module
Refer to page 21
Replace resonator (X501)
Is operation normal?
16
Page 16
Remove the power cord and plug it in
again in approx. five seconds
NO
Does it start operating when
Is DC voltage of PCB
display normal?
NO
Is transmission display of the
remote control unit blinking?
#1 and #3 of CN78
Does the 'beep' sound from the
NO
NO
Is DC voltage of the PCB module
a power cord and
a terminal tap
Are voltages of #8 (IC04 : compressor),
#6(IC04 INdoor fan) of Micom normal? :
5VDC is voltage of #60 (IC04 : indoor fan)
DC5V
NO YES
Is voltage of #33 terminal of Micom (IC04)normal?
Is voltage of #18 terminal of Micom (IC04)normal?
Is voltage of #52 terminal of
Are voltages of #48 and #49 of
NO
NO
YES
OK
Does the lamp blink?
YES
YES
you push the On/Off button
on the remote control?
NO
NO
YES
main unit?
YES
NO
normal?
YES
YES
of Micom normal?
10ms
NO
0VDC
5VDC
NO
YES
Micom (IC04) normal?
10ms
YES
NO
Micom (IC04)normal?
250ns
YES
Replace
Micom
Normal
Refer to remote control
unit abnormal diagnosis
Replace the PCB module
Refer to page 21
Are voltages of RY71(Compressor)
and RY72(outdoor fan) normal?
DC12V Is voltage of SS71(indoor fan)?
YES NO
Check connections
Replace RY71,
of compressor
RY72 and
outdoor fan
SS71
and indoor fan
Is output voltage of ICO2 normal?
NO
YES
Replace PCB module
Replace ICO2
Refer to page 21
Is voltage output terminal of
D101~D105(IN4007) normal?
YES NO
Replace IN4007
OK