LG 50PC5DC Service Manual page 23

TROUBLESHOOTING GUIDE
HDMI doesn't display
Check input connect P7007.
Can you see the normal waveform?
YES
Check DDC communication lines(IC7013 Pin5,6)
YES
Check HDCP communication lines(IC7005 Pin5,6)
YES
Check the input of MST3361(IC7004)
This signal is TMDS.
Can you see the normal waveform?
YES
Check the output of MST3361(IC7004 ).
Can you see the normal waveform?
YES
Check the input and output of
BCM3550(IC4006). Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
NO
P7007 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
After checking the trace of TMDS lines and power of
MST3361, you should decide to replace MST3361 or not.
NO
After checking the Power of MST3361 you should
decide to replace MST3361 or not.
This board has big problem because Main
YES
chip(BCM3550) have some troubles.
After checking thoroughly all path once again, You
should decide to replace BCM3550 or not.