LG LH-CX640 Series Service Manual page 29

3-12
(3)
When
the
C(Color)
signal
doesn't
appear
on the
screen
in
PB
Mode,
Is
5.2VT/5.3VAapplied
to
the
IC301
Pins24,
42,
55,
72,
91.
Is the Color
Rotary
signal
applied
to
the
IC301
Pin70?
Checkthe
line
of
the
5.2VT/
5.3VALine.
(Power Circuit)
Replace the
X301.
Check
the
Color
Pass.
Check
the
Color Rotary
Circuit.
(IC501 Pin99 )
Check
the
Color
Rotary
level.
(Check
the
R303)
Doesthe
X301(4.43MHZ)
oscillate?
Replace
the
IC301.
Does
the
Color
signal
appear
at
the
IC301
Pin21?
Is
Color
Rotary
\"H\"
about
3.4V?
Replace
the
IC301.
NO
NO
NO
YES
YES
YES
YES
NO NO
NO
YES
Does
the
Color
signal
appear
at
the
IC301
Pin25
?