LG 47LH90 (CHASSIS:LA92C) Service Manual ▷ View online
LA92B-LH40/LH55 Trouble shooting guide – HDMI
Audio(In)
Check input connect JK500,JK501,JK502,JK503
Can you see the normal waveform?
Can you see the normal waveform?
JK500,JK501,JK502,JK503 may have problem. Replace this Jack.
After checking the Power of this chip, you should decide to replace this or not.
After checking the Power of this chip, you should decide to replace this or not.
YES
YES
YES
NO
NO
NO
NO
After checking the Power & Select Pin & Etc of this chip, you should decide to replace this or not.
Check DDC communication lines
(IC502)
(IC502)
Check the output of TDA9996HL(IC502)
_HDMI1,2,3 or HDMI4. .
Can you see the normal waveform?
_HDMI1,2,3 or HDMI4. .
Can you see the normal waveform?
Check HDCP communication lines(IC105)
YES
Check the Output (Pin Audio_MASTER_CLK ,MS_LRCK
MS_SCK,MS_LRCH) of LGE3159(IC100).
Can you see the normal waveform?
MS_SCK,MS_LRCH) of LGE3159(IC100).
Can you see the normal waveform?
Check IC600(NTP-3100L) L606/L607
YES
NO
After checking the Power & Select Pin & Etc of this chip, you should decide to replace this or not.
NO
After checking the Power & Select Pin & Etc of this chip, you should decide to replace this or not.
LA92B-LH40/LH55 Trouble shooting guide – Speaker
Audio(Out)
Check the output (Pin A8,B7,C7,D8) of LGE3159(IC100).
Measure waveform at R160,R161,R162,R163 because it’s more easy to check.
Can you see the normal signal?
Measure waveform at R160,R161,R162,R163 because it’s more easy to check.
Can you see the normal signal?
Check the input (Pin 7,17,18,19) of NTP3100((IC600).
Can you see the normal waveform?
Can you see the normal waveform?
YES
NO
NO
This board has big problem because Main chip(BCM3553) have some troubles.
After checking thoroughly all path once again, You should decide to replace BCM3553 or not.
After checking thoroughly all path once again, You should decide to replace BCM3553 or not.
After checking audio signal line, you should decide to replace item or not.
YES
NO
After checking the Power & I2C & Reset of this chip, you should decide to replace this or not.
NO
YES
After checking audio signal line, you should decide to replace item or not.
Check the connector & Speaker
Check the Output (Pin Audio_MASTER_CLK ,MS_LRCK
MS_SCK,MS_LRCH) of LGE3159(IC100).
Can you see the normal waveform?
MS_SCK,MS_LRCH) of LGE3159(IC100).
Can you see the normal waveform?
Check IC600(NTP-3100L) L606/L607
YES
LA92B-LH40/LH55 Trouble shooting guide – SPDIF
Audio(Out)
Check the output (Pin E9) of LGE3159(IC100).
Measure waveform at R159 because it’s more easy to check.
Can you see the normal signal?
Measure waveform at R159 because it’s more easy to check.
Can you see the normal signal?
Check the input of JK601.
Can you see the normal waveform?
Can you see the normal waveform?
YES
NO
NO
This board has big problem because Main chip(LGE3159) have some troubles.
After checking thoroughly all path once again, You should decide to replace LGE3159 or not.
After checking thoroughly all path once again, You should decide to replace LGE3159 or not.
After checking audio signal line, you should decide to replace item or not.
YES
After checking the Jack, you should decide to replace item or not.