LG 47LH90 Service Manual page 46

LH40/LH55 Trouble shooting guide – HDMI
Check input connect JK500,JK501,JK502,JK503
Can you see the normal waveform?
YES
Check DDC communication lines
(IC502)
YES
Check HDCP communication lines(IC105)
YES
Check the output of TDA9996HL(IC502)
_HDMI1,2,3 or HDMI4. .
Can you see the normal waveform?
YES
Check all power domain of LGE7329 (IC801)
(3.3V, 1.9V_CORE,1.26V)
& crystal output (X800 / 12MHz)&FRC_RESET
Measure Power & waveform at L800,L801,L802,L803,L804,L806
because it's more easy to check.
Can you see the normal waveform?
YES
This board has big problem because FRC chip(LGE7329) have some troubles.
After checking thoroughly all path once again, You should decide to replace LGE7329.
Although you replace it, you cannot see normal display, decide to replace Main chip(LGE3159)
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Only for training and service purposes
NO
JK500,JK501,JK502,JK503 may have problem. Replace this Jack.
NO
After checking the Power of this chip, you should decide to replace this or not.
NO
After checking the Power of this chip, you should decide to replace this or not.
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.
Video
LGE Internal Use Only