LG Electronics 20LS7D(C)-UB Flat Panel Television User Manual


 
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5. HDMI doesn't display
Check input connect J7101.
Can you see the normal waveform?
J7101 may have problem. Replace this Jack.
Check DDC communication lines(IC702 Pin5,6)
After checking the Power of this chip, you should
decide to replace this or not.
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Check HDCP communication lines(IC701 Pin5,6)
After checking the Power of this chip, you should
decide to replace this or not.
Yes
Check the input of MST3382M(IC7012).
This signal is TMDS.
Can you see the normal waveform?
After checking the trace of TMDS lines and power
of MST3382M, you should decide to replace
MST3382M or not.
Check the output of MST3361(IC7012)
Can you see the normal waveform?.
After checking the Power of MST3361 you should
decide to replace MST3361 or not.
Check the input and output of BCM3550(IC1001).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
This board has big problem because
Main chip(BCM3550) have some troubles.
After checking thoroughly all path once again,
You should decide to replace BCM3550 or not.