LG Electronics 42CS669C-ZD service manual Troubleshooting, Power-up boot check, No No No No No

TROUBLESHOOTING

1. Power-up boot check

Check stand-by Voltage.	No
P403 9~12pin : +3.5V_ST
ok
Check Micom Voltage.	No
L404 : +3.5V

ok

No

Check X201 clock. 24 MHz

ok

Check Power connector.

Replace L404.

Replace X201.

ok

Main B/D 3.5V Line

Short Check

ok

Replace Power board.

No

Check P403 PWR_ON.

1pin : 3.3V

No

Re-download software. Replace Mstar(IC101) or Main board.

ok

Check Multi Voltage. P403 2pin:24V, 17pin:12V

ok

Check IC402/3/7 Output Voltage.

IC402 : 2.5V

IC403 : 1.1V

IC407 : 1.5V

Q403 : 3.3V

ok

Check LVDS Power Voltage.

Q409 : 12V

ok

Check Mstar LVDS Output

ok

Check Inverter Control & Error Out. P403 18 pin : High

P403 24 pin : low

ok

Change Module.

No

No

No

No

No

Replace Power Board.

Replace IC402/3/7, Q403.

Replace Q409.

Replace Mstar(IC101) or Main Board.

Check Power Board or Module.

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