Samsung AQ18A9(0)RCF - Abnormal Diagnosis by Symptom

16
Troubleshooting (cont’d)
ΙΙΙ
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
Replace
PCB display
Is DC voltage of PCB
display normal?
Remove the power cord and plug
it in again in approx. 5 seconds
Does the lamp blink?
Does it start operating when you
push the On/Off button of the
remote control?
Is transmission display of the
remote control unit blinking?
Does the ‘beep’ sound from
the main unit?
Is DC voltage of the PCB
module normal?
Are voltages of #8(IC04 : compressor),
#7(IC04 : 4way valve) and #6(IC04 : outdoor fan)
of Micom normal? 5VDC is voltage
of #60((IC04 : indoor fan) of Micom normal?
Is voltage of #33 terminal of Micom (IC04)normal?
0VDC
Is voltage of #18 terminal of Micom (IC04)normal?
5VDC
Is the rating Voltage ±10%
range applied to the between
#1 and #3 of CN78
Check linkage
between
a power cord and
a terminal tap
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
YES
YES
NO
YES
NO
YES
YES
YES
NO
YES
YES
YES
DC5V
10ms
10ms
100ns
NO
NO
OK
YES
YES
YES
YES
NO
NO
YES
Normal
Refer to remote control unit
abnormal diagnosis
Replace PCB module
Refer to page 21
Is output voltage of ICO2 normal?(DC5V)
Check connections
compressor, outdoor
fan and indoor fan
Are voltages at RY71(Compressor)
and RY72 (Outdoor fan) normal?
; DC12V
Is voltage at SS71(indoor fan)?
Replace RY71,
RY73, RY72
and SS71
NO
NO
NO
Is voltage output terminal of
D101~D105(IN4007) normal?
Replace
IC02
Check PCB pattern
Replace PCB module
Refer to page 21
Replace IN4007
Replace
Micom
Is voltage of #52 terminal of
Micom (IC04)normal?
Are voltage of #48 and #49 of
Micom (IC04)normal?
NO
NO
NO
YESNO
NO
NO
YES
Is operation normal?
OK
Replace resonator (X501)
AQ18A5(6)RC SM_E_15778 2/12/04 9:10 PM Page 16