Read LG 47LG30D (CHASSIS:LB81A) Service Manual online
- 18 -
C
2008
6. HDMI doesn’t display
Check input connect J900 , J901, J902
Can you see the normal waveform?
Check DDC communication lines(IC900,
IC901, IC903 Pin5,6)
Check the input of HDMI Seitch(IC902)
This signal is TMDS.
Can you see the normal waveform?
YES
YES
NO
J900 , J901, J902
may have problem. Replace this Jack.
Check the output of HDMI Switch(IC902).
Can you see the normal waveform?
YES
YES
NO
After checking the trace of TMDS lines and power of
HDMI Switch, you should decide to replace HDMI
Switch or not.
NO
NO
After checking the Power of this chip, you
should decide to replace this or not.
After checking the Power of HDMI Switch you
should decide to replace MST3361 or not.
YES
Check HDCP communication lines(IC902)
NO
After checking the Power of this chip, you
should decide to replace this or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
Click on the first or last page to see other 47LG30D (CHASSIS:LB81A) service manuals if exist.