Read LG 22LS3500 / 22LS3700 (CHASSIS:LB21A) Service Manual online
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TROUBLE SHOOTING
1. Power-up boot check
Check stand-by Voltage.
IC3307
Pin 1, L3317 : +3.5V_ST
pin 5, R3387 : +3.5V_ST
Check Power connector
Main B/D 3.5V Line
Short Check
Check X201 clock
24 MHz
Replace X201
Check Q3302
RL_ON_BUFFER : 3.3V
Replace Mstar(IC101) or Main board
Check Multi Voltage
P3300 1~5 pin: +24V
JK3300, L3304 : +24V/+15V
Replace Adapter
Check Error Out & Inverter Control
P3300 pin 11 : Low
P3300 pin 12 : High
Check Power Board or Module
Check IC Output Voltage
IC3310 : 2.5V
IC3304 : 1.2V
IC3305 : 1.5V
Q3312 : 3.3V
Replace IC3304/3305/3310 or Q3312
Re-download software.
Check LVDS Power Voltage
Q3307 : 12V
Replace Q3307
Check Mstar LVDS Output
Replace Mstar (IC101) or Main Board
Change Module
ok
ok
ok
ok
ok
ok
ok
ok
No
No
No
No
No
No
No
No
No
ok
Replace Power board.
ok
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