Samsung AQ09MSBN Service Manual page 38

12-3 Breakdown diagnosis by symptoms
12-3-1 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
Unplug the power cord and
plug it after 5 seconds
Press the Power Button on the
remote control unit to
operate the air conditioner
Check the indoor unit
Check whether 2 wires
connected correctly to the
terminal block and control board.
Check whether the fuse on the
control board is normal.
FUSE(F701): T2.5[A]/250[V]
Check the output of SMPS
on the control board.
Input power: AC230±15%[V]
IC02 Input: DC12[V]
IC02 output: DC5[V]
Check the setting temperature
Samsung Electronics
does not operate
control board
of power cord are
Yes
Yes
Yes
operate
No
No
No
Troubleshooting
Check the display board
Reconnect wires correctly
Replace fuse
PCB should be replaced
12-3