Samsung AS09A5MA, Service Manual

10

3-2 Fault Diagnosis by Symptom

3-2-1 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

Replace  PCB

display

Is DC voltage of PCB

display normal?

Remove power cord and plug in 

again in approx. 5 seconds

Is operation lamp blinking?

Does operation start when

ON/OFF button on the remote

controller unit pushed?

Is transmission display of the 

remote controller unit blinking? 

Is "beep"sound heard from the main

unit?

Is DC voltage of the PCB module

normal?

Are voltages of #8 (compressor), 

#7(4 way valve) and #6 (outdoor fan) 

of the micom normal? 5VDC 

Is voltage of #60 (indoor fan) of the

micom normal?

Is voltage at #50 terminal of the Micom normal?

0VDC

Is voltage at #18 terminal of the Micom normal?

5VDC

Is rating voltage ±10% range

applied to the primary side(~,~) 

of the “BD71”

•Check linkage between

power cord and

terminal tap

•Check fuse

Is 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 fault diagnosis

Replace PCB

module.

Is output voltage of ICO2 normal?

Check connections

compressor  

and indoor fan.

Are voltages at RY71(Compressor) 

normal? DC12V

Is voltage at SS71(indoor fan)

Replace RY71

and SS71

NO

NO

NO

Is voltage output  terminal of

TLP180(PC02) normal?

Replace ICO2

Check PCB pattern.

Replace main PCB.

Replace TLP180(pc02)

Replace

micom

Is voltage at #52 terminal of the micom

normal?

Are voltage at #48 and #49 of the

micom normal?

NO

NO

NO

YES

NO

NO

NO

YES

OK

Is operation normal?

Replace resonator (X301)

 9-00187A(1)-TS  5/16/01 2:01 PM  Page 10