Samsung Electronics
28
6-3 Breakdown diagnosis by symptoms
6-3-1 No Power (completely dead)-Initial diagnosis
1. Checklist :
1) Is input voltage normal?
2) Is AC power linked correctly?
3) Is input voltage of DC regulator IC KA7805 (IC02) normal? (11VDC-12.5VDC)
4) Is output voltage of DC regulator IC KA7805 (IC02) normal? (4.5VDC-5.5VDC)
2. Troubleshooting procedure
does not operate
Yes
Yes
Yes
Unplug the power cord and plug it after 5 seconds
◆
Check the setting temperature
operate
◆
Check the display board
◆
Check the indoor unit control board
No
Reconnect wires correctly
Check whether two wires
of power cord are connected correctly to the
terminal block and control board.
Press the Power Button on
the remote control unit to operate the air
conditioner
No
Replace fuse
Check whether the fuse
on the control board is normal.
F701: 3.15[A]/250[V]
No
Replace the control board
Check the output of
SMPS on the control board.
Input power: AC230±15%[V]
IC02 Input: DC12[V]
IC02 output: DC5[V]
Summary of Contents for US18WJWB
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