LG CM9750 - System Part

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ELECTRICAL TROUBLESHOOTING GUIDE
2. SYSTEM PART
Power on.
System part OK.
Check FFC cable.
Check SMPS board.
Check FFC cable.
Check MAIN board.
Check SMPS board.
Replace VFD301.FL+/- & VKK voltage OK?
Replace LED
(LD311, LD313),
(LD301, LD303)
Check MAIN board.
“HELLO”
Display on MLD
OK?
Top LED
(LD311, LD313),
(LD301, LD303)
Turn on?
When turn
the volume, count is
change?
NO
NO
NO
NO
NO
NO
NO
NO
NO
CN605
cable connection
OK?
CN605 pin24
+12 V OK?
Check
CN605 pin5, 6
I2C data OK?
CN605
pin8, 9, 10 data signal
OK?
CN605
pin14, 15, 16, 24 power
OK?
YES
YES
YES
YES
YES
YES
YES
YES