LG DC593W Manual page 23

3. Y/C CIRCUIT
(2) When the Y(Luminance) signal doesn't appear on the screen in PB Mode,
Is 5V applied to the IC301
Pins12, 36, 61, 67, 90, 96?
YES
Is the I C Bus siganl applied
2
to the IC301 Pins62, 63?
YES
Does the normal RF signal
appear at the IC301 Pin 79?
YES
Does the Y(Luminance)
signal appear at the IC301
Pin18?
YES
Is the Y(Luminance) Video
waveform showed up at the
IC301 Pin39?
YES
Replace the IC301.
NO
Check the line of the REG
5V Line. (Power Circuit)
NO
Refer to 'SYSTEM I
CHECK Trouble Shooting'.
NO
Is the V.H.S/W signal
applied to the IC301 Pin81?
Does the Rectangular
waveform(5V) appear at
the IC301 Pin81(V.H.S/W)
Clean the Drum.
NO
Check the path of the
Y(Luminance) signal.
NO
Check the path of the
Y(Luminance) signal.
3-11
C BUS
2
NO
YES
NO
YES
NO
YES
YES
Check the System Circuit.
(IC501 Pin24)
Check the V.H.S/W level.
Replace the IC301.