LG 47LU65 (CHASSIS:LA86D) Service Manual ▷ View online
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A SMPTE Color bar signal is recommended for this
trouble shooting.
Check DDC communication lines
(IC601, IC602,IC603, IC701)_5&6 PIN must be 5V
To be able to check the waveforms of HDMI input,
it requires a high speed & bandwidth oscilloscope
Check input connect JK600,JK601,JK602,JK708
Probe at Clk positive and nagative points.
This Clk speed can be up to 225Mhz, depending on
what kind of source comes in.
Can you see the normal waveform? Refer to figure 1
Replace
JK600,JK601,JK602,JK708
Replace the defective IC
Check the output of PI3HDMI341ATR(IC600)
_PIN 25/26/28/29/31/32/34/35,TMDS141RHAR(IC703)
_PIN 9/10/12/13/15/16/18/19
You can easily check pin 34/35PIN of IC600
(TMDS CLK OUTPUT),18/19PIN of IC703
Can you see the normal waveform? Refer to figure 2
HDMI-Video
YES
YES
Check HDCP communication lines(IC102)_5&6 PIN
must be 5V
YES
Figure 1
NO
NO
Replace IC102
Replace IC600 for HDMI 1/2/3
Replace IC703 for HDMI4
NO
NO
Figure 2
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Check TU1 Pin14(SIF)
Can you see the normal signal?
Refer to figure 1
You should check power line
(PIN3_Must be 5V )& & IIC lines
(PIN 7& 8_Must be 5V.
Check the input (Pin AN23) of BCM355x((IC100).
Measure waveform at C665 because it
’s more
easy to check.
Can you see the normal waveform? Refer to
figure 2
Replace IC100
TV/CATV-Audio(In)
YES
YES
NO
Could you measure voltage of TU1
(PIN3_Must be 5V )& IIC lines
(PIN 7& 8_Must be 5V)?
Are they all normal?
You should replace TUNER.
NO
NO
Figure 1
Figure 2
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Check JK701, JK707, JK700, JK702, JK703.
Can you see the normal waveform? Refer to
figure 1
JK701, JK707, JK700, JK702, JK703 may have
problem. Replace this Jack.
AV/Component/RGB_PC-Audio(In)
YES
NO
Check the input (Pin AIN6A, AIN6B, AIN1A,
AIN1B, AIN3A, AIN3B, AIN4A, AIN4B, AIN2A,
AIN2B) of CS5345(IC500).
Can you see the normal waveform? Refer to
figure 2
After checking audio signal line, you should
decide to replace item or not.
YES
NO
Check the Output (Pin SDOUT(41), SCLK(42),
LRCK(43)) of CS5345(IC500).
Can you see the normal waveform? Refer to
figure 3/4/5
After checking the Power & MLCK & reset of this
chip, you should decide to replace this or not.
NO
YES
Check the input (Pin AH24,AJ24,AK24) of
BCM3553((IC100).
Measure waveform at R561,R554,R555 because
it
’s more easy to check.
Can you see the normal waveform? Refer to
figure 3/4/5
After checking audio signal line, you should
decide to replace item or not.
NO
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
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Check input connect JK600,JK601JK602,JK708
Can you see the normal waveform?
Replace JK600,JK601,JK602,JK708
Check DDC communication lines
(IC600,IC601, IC602, IC701_5&6 PIN must be 5V)
Replace the defective IC
Check HDCP communication lines
(IC102_5&6 PIN must be 5V)
Replace IC102
YES
YES
Check the output of PI3HDMI341ATR(IC600),
TMDS141RHAR(IC703).
Can you see the normal waveform?
Replace IC600 for HDMI 1/2/3
Replace IC703 for HDMI 4
YES
NO
NO
NO
NO
HDMI-Audio(In)
* Since HDMI AUDIO Data is contained with Video Data.
We cannot measure waveform for only Audio.
We can check I2S output from BCM3553(IC100).
This is explained after page Audio (Out).
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