Fault Diagnosis By Symptom - Samsung AD26B1C13 Service Manual

3-3 Fault Diagnosis by Symptom

3-3-1 No Power (completely dead)-Initial diagnosis
1) Checklist :
(1) Is input voltage normal?
(2) Is AC power linked correctly?
(3) Is output voltage of DC regulator IC KA7805 (IC02) normal? (4.5VDC-5.5VDC)
2) Troubleshooting procedure
YES
Is DC voltage of PCB
Is rating voltage ±10%
Replace
range applied to the
PCB display
primary side (~,~)
•Check linkage between
power cord and
terminal tap
•Check fuse
Is 14~18VAC appear in
the secondary side (+, -)
Replace
SMPS PARTS
Replace resonator (X301)
Is operation normal?
Remove power cord and plug in
NO
run/stop button on the remote
display normal?
NO
Is transmission display of the
remote controller unit blinking?
of the "BD71"
Is "beep"sound heard from the
NO
NO
Is DC voltage of the PCB module
5VDC Is voltage of #60 (indoor fan)
of "BD71"
DC5V
NO YES
Is voltage at #52 terminal of the
Are voltage at #48 and #49 of the
NO
NO
YES
OK
again in approx. 5 seconds
Is operation lamp blinking?
YES
Does operation start when
controller unit pushed?
NO
YES
main unit?
YES
normal?
YES
of the micom normal?
10ms
NO
micom normal?
10ms
NO
YES
micom normal?
250ns
YES
Replace micom
YES
Normal
NO
Refer to remote control
unit fault diagnosis
NO
Replace PCB module.
DC12V
YES
Is voltage at SS71(indoor fan)
YES
Check connections
Replace RY71,
compressor 4-way
RY73, RY72 and
valve, outdoor fan and
indoor fan.
Is output voltage of ICO2 normal?
YES
Check PCB pattern.
Replace ICO2
Replace main PCB.
Is voltage output terminal of
TLP180(PC02) normal?
YES
Replace TLP180(pc02)
OK
NO
SS71
NO
NO
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