LG LST-5600A Service Manual page 27

(C2)
YES
Check tuner output composite signal
(C615) FIG.05
OK
Check NTSC decoder.
YES
Is there any quantize noise ?
YES
END
FIG.05
CVBS signal from TU300
When NTSC is main
NG
power check: L602 5V
NG
Analog input: IC606 (44)
Reference clock oscillation : X601 FIG.06
Pixel clock: 13.5MHz continuous
Clock in IC606 (28). FIG.07
Hsync out: 15.7KHz negative
pulse in IC606 (36). FIG.08
Vsync out: 59.94Hz negative
pulse in IC606 (35). FIG.09 top
Field ID : 29.97Hz pulse in
IC606 (34). FIG.09 bottom
IIC: IC606 (10(SCL), 11(SDA))
YES
3-20
Check tuner block(TU300)
Check digital output pin short
in IC606 pin 12~19, 23~26, 30~33.