16
Troubleshooting (cont’d)
ΙΙΙΙΙΙ
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. five seconds
Does the lamp blink?
Does it start operating when
you push the On/Off button
on 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),
#6(IC04 INdoor 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 voltage rating within ±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
250ns
NO
NO
OK
YES
YES
YES
YES
NO
NO
YES
Normal
Refer to remote control
unit abnormal diagnosis
Replace the PCB module
Refer to page 21
Is output voltage of ICO2 normal?
Check connections
of compressor
outdoor fan
and indoor fan
Are voltages of RY71(Compressor)
and RY72(outdoor fan) normal?
DC12V Is voltage of SS71(indoor fan)?
Replace RY71,
RY72 and
SS71
NO
NO
NO
Is voltage output terminal of
D101~D105(IN4007) normal?
Replace ICO2
Replace PCB module
Refer to page 21
Replace IN4007
Replace
Micom
Is voltage of #52 terminal of
Micom (IC04) normal?
Are voltages of #48 and #49 of
Micom (IC04)normal?
NO
NO
NO
YES
NO
NO
NO
YES
OK
Is operation normal?
Replace resonator (X501)
AS18A5(6)RC_E 1/7/04 6:08 PM Page 16
