Service manual

14
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?
(2) Is AC power linked correctly?
(3) Is output voltage of DC regulator IC KA78L05 (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 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 #33 (IC04 : compressor)
of Micom normal? 5VDC
Is voltage of #32 (IC04 : indoor fan) of
Micom normal?
Is voltage of #10(IC04) terminal of Micom normal?
0VDC
Is voltage of #9(IC04) terminal of Micom normal?
5VDC
Is voltage rating within ±10%
range applied to the primary
side(~,~) of the “BD71”?
Check linkage between
a power cord and
a terminal tap
Check fuse
Does 325VDC appear in
the secondary side (+, -)
of “BD71”?
Replace
SMPS PARTS
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 PCB
module .
Is output voltage of ICO2 normal?
Check connections
of compressor
and indoor fan.
Are voltages of RY71(Compressor)
normal? DC12V
Is voltage of SS71(indoor fan)?
Replace
RY71 and
SS71
NO
NO
NO
Is voltage output terminal of
PC814A(PC02) normal?
Replace ICO2
Check PCB pattern
Replace the main PCB
Replace PC814A(PC02)
Replace
Micom
Is voltage of #3(IC04) terminal of
Micom normal?
Are voltages of #12(IC04) and
#11(IC04) of Micom normal?
NO
NO
NO
YESNO
NO
NO
YES
OK
Is operation normal?
Replace resonator (X301)
AS07AS(6)MA SM_E_15774 2/12/04 9:19 PM Page 14