Samsung MH18ZC1(C2)-09 Service Manual page 32

5-4-3 No Power (Outdoor unit)
1) Inspection items
(1) A Is the power source normal (The rating Voltage ±10% range)?
(2) Is the outdoor power connected normally? ((1) of terminal : L, (2) of terminal : N, (3) of ter-
minal : communication) ?
(3) Check whether the display of outdoor PCB(SEG1) is shown in the order of A- B - C when
the power is applied.
If the display (SEG 1) is not shown the inspection and repair shall be performed in the
sequence of the following:
2) Inspection sequence
Check the com-
munication of PCB
Y
Normal of
and whether the
outdoor PCB
LED 1 is continu-
ously flickering.
Replace the
transformer
Replace the fuse
(F701) 250V 3.15A.
Measurement of resistance
N of power transformer
Are they as follows?
1st side 190 ~ 210Ω
2nd side 0.9 ~ 1.1Ω
Y
Assemble the transformer
in the normal way.
Samsung Electronics
Put the power off and put it on after
Is the display of PCB shown in the
Y
N
Are the power cord ((1) L, (2) N) and
communication line (3) of outdoor termi-
Is the terminal of PCB terminal (RY71,
72, 73) are assembled in the correct
Y
Insert the primary side of power trans-
N
former in the terminal GT01 and then is
the voltage of secondary side normal?
Is the fuse (F101, 250V 2 A) blown out?
Check whether the output voltage of
Check whether the output voltage of
Replace the outdoor unit Ass'y main PCB.
5 seconds.
sequence of A-B-C?
N
nal block connected correctly?
Y
position?
Y
Is the fuse open? (F701)
N
(AC 15V- AC 25V)
Y
N
IC01 (KA 7812) is DC 12V.
Y
IC02 (KA 7805) is DC 5V.
Y
Troubleshooting
Reinstall the power cord and
N
communication line with the ref-
erence of installation manual.
After watching the display of
N
PCB board, assemble the color
and shape of housing correctly
as follows:
BLK
BLK
WHT
WHT
RED
RED
Y
Replace the fuse F101 (250V 2 A).
Check and Replace the rectifying
N
diode of power side (D101 - D104)
and KA 7812.
N
Replace the IC 02 (KA7805)
5-9