Fault Diagnosis By Symptom - Samsung SH18AP0D Service Manual

6-2 Fault Diagnosis by Symptom

6-2-1 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
N Check the indoor unit
control board
Check whether two wires
of power cord are
connected correctly to the
terminal block and control board.
Check whether the fuse on the
control board is normal.
FUSE: 3.15[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]
N Check the setting temperature
22
operate
does not operate
Yes
Yes
Yes
N Check the display board
No
Reconnect wires correctly
No
No
PCB should be replaced
Replace fuse
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