LG 50PC5DC Service Manual page 20

TROUBLESHOOTING GUIDE
Video doesn't display
Check J5007 Pin3C
Can you see the normal waveform?
YES
Check the input(Pin1 or Pin8) of AV
switch(IC5003). Pin1 is for video1,Pin8 is for
video 2.
Can you see the normal waveform?
YES
Check the output(Pin56) of AV switch(IC5003).
Can you see the normal waveform?
YES
Check the input(Pin1) of LPF(IC4006).
Can you see the normal waveform?
YES
Check the output(Pin8) of LPF(IC4006).
Can you see the normal waveform?
YES
Check the input(PinH26) of BCM3550(IC4006).
Measure waveform at C1010 because it s more
easy to check.
Can you see the normal waveform?
NO
J5007 may have problem. Replace this Jack.
NO
After checking the Power of AV switch you should
decide to replace AV switch or not.
NO
After checking the Power of AV switch you should
decide to replace AV switch or not.
NO
After checking the Power of LPF you should decide to
replace LPF or not.
NO
After checking the Power of LPF you should decide to
replace LPF 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.