LG 37LT560C / 37LT560E (CHASSIS:LA2AC) Service Manual ▷ View online
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12. External Speaker Out
(1) Connect external speaker to speaker out port with phone jack on TV side as below
(2) Check the Max. speaker output is 1W or not. Sine wave with 1KHz will be displayed
(3) Check Both of the signal in speaker.
(Power only mode -> Fived 1W Default)
-> Check the input signal(1KHZ, Sine wave) and the wave of output by utilizing oscilloscope.
Recommended Input Signal
: RF, 1kHz, Sine wave
: RF, 1kHz, Sine wave
*
must remove Ground pin in plug
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TROUBLESHOOTING
1. Power-up boot check
Check stand-by Voltage.
P403 9~12pin : +3.5V_ST
Check Power connector
Main B/D 3.5V Line
Short Check
Check X201 clock
24 MHz
Replace X201
Check P403 PWR_ON.
1pin : 3.3V
Replace Mstar(IC101) or Main board
Check Multi Voltage
P403 2pin:24V ,17pin:12V
Replace Power Board
Check Inverter Control & Error Out
P403 18 pin : High
P403 24 pin : low
Check Power Board or Module
Check IC402/3/7 Output Voltage
IC402 : 2.5V
IC403 : 1.1V
IC407 : 1.5V
Q403 : 3.3V
Replace IC402/3/7, Q403
Re-download software.
Check Micom Voltage
L404 : +3.5V
Replace L404
Check LVDS Power Voltage
Q409 : 12V
Replace Q409
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board
Change Module
ok
ok
ok
ok
ok
ok
ok
ok
ok
No
No
ok
Replace Power board.
ok
No
No
No
No
No
No
No
No
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2. Digital TV Video
Check RF Cable & Signal
Check Tuner 3.3V Power
L3703
Replace L3703
Check Tuner 1.8V Power
IC3703 2 pin : 1.8V
Check IF_P/N Signal
TU3700 10/11 Pin
Replace IC3703
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
ok
ok
ok
ok
No
No
No
No
Bad Tuner. Replace Tuner.
3. Analog TV Video
Check RF Cable & Signal
Check Tuner 3.3V Power
L3703
Replace L3703
Check Tuner 1.8V Power
IC3703 2 pin : 1.8V
Check CVBS Signal
TU3700 8 Pin
Replace IC3703 .
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
ok
ok
ok
ok
No
No
No
No
Bad Tuner. Replace Tuner.
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4. AV Video
Check input signal format.
Is it supported?
Check AV Cable for damage
for damage or open conductor
Check JK1604, CVBS Signal Line
R246
ok
ok
ok
No
Replace Jack
ok
Check CVBS_DET Signal
Replace R1666
No
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
No
5. RGB Video
Check input signal format.
Is it supported?
Check RGB Cable conductors
for damage or open conductor
Check EDID
I2C Signal
R1140, R1139(SDA,SCL)
Check JK1104
H/V_Sync/R/G/B Signal Line
ok
ok
ok
No
No
re-download EDID data ,Replace Mstar(IC101) or Main Board
ok
Replace Jack
Check DSUB_DET
Replace R1146 or R1147
No
Check Mstar LVDS Output
Replace Mstar(IC101) or Main Board.
ok
No
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