LG LS-J0762NM, Service Manual, Page: 52 / 82

Electronic Parts Troubleshooting Guide
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Refer to electronic contorol device drawing & schematic diagram.
The Product doesn’t operate at all.
Turn off the main power and wait to 10 seconds
Turn on the main power again.
Does "Beeping" sound is made from the indoor unit?
• Primarily, the operating
condition of Micom is O.K.
• Check CN-DISP1
CN-DISP2
Check the voltage of power(AC220V/AC240V, 50Hz).
• The voltage of main power.
• The voltage applied to the unit.
• The connecting method of Indoor/Outdoor connecting cable (each color)
• The P.W.B. Ass'y
(Fuse, Noise Filter, SMPS Transformer, Bridge Diode, etc.)
Trouble 1
NO YES
The operation check of the Indoor P.C.B. Ass'y
Procedure
1) The input voltage of SMPS
2) The output voltage of SMPS
4) IC04D(7805)
5) IC01A(KIA7036)
Specification
1) AC230V ± 30V
: Check the rated voltage
2) 12V ± 3V
4) DC5V
5) The voltage of micom pin 19
: DC4.5V
↑
Remedy
1) Replace
SMPS
2) Replace
SMPS
4) Replace IC04D.
5) Replace IC01A.