Read LG 42LV5400 (CHASSIS:LA12E) Service Manual online
1. Trouble shooting - No power
Check stand-by Voltage.
P501 9~12pin : +3.5V_ST
Check Power connector
Main B/D 3.5V Line
Short Check
Check X602 clock
32 KHz
Replace X602
Check P501 PWR_ON.
1pin : 3.3V
Replace Micom(IC602 ) or Main board
Check Multi Voltage
P501 2 pin : *24V , 17 pin : 12V
Replace Power Board
Check Inverter Control
P501 18 pin : High
Check Power Board or Module
Check IC501/4/5/8 Output Voltage
IC501 : 0.9V, IC508 : 1.5V
IC504 : 2.5V ,IC505 : 3.3V
Replace IC501/4/5/8
Re-download Micom software.
Check Micom Voltage
IC602 pin 48 : +3.5V
Replace L503
Check LVDS Power Voltage
Q507 : 12V
Replace Q507
Change Module
ok
ok
ok
ok
ok
ok
ok
ok
ok
No
No
No
No
No
No
No
No
No
Check X101 Clock
54 MHz
Replace X101
ok
No
Replace Power board.
ok
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