Service manual

3-12
3. Y/C CIRCUIT
(3)
PB Mode
Color Signal does not
apper On Screen.
Check the V.H/SW level of
System.
Is I
2
C BUS applied at
IC301 Pins62, 63?
Check System.
Is V.H/SW normal at
IC301 Pin81?
Clean Head.
Does RF signal appear at
IC301 Pin79?
YES
YES
YES
Does Video Signal appear
at IC301 Pins58, 60 ?
YES
Does Color Signal appear
at IC301 Pins55, 54?
YES
Check EE MODE.
Is IC301 supplied at Pin90?
NO
NO
NO
Check 5V power part.
NO
NO
Check 5V power part.
NO
Check IC301 X301.
NO
Check path from IC301
Pin69 to IC301 Pin44.
NO
NO
YES
IS 5V Power Supplieda at
IC301 Pins12, 36, 61, 67,
90, 96?
Does 3.58MHz appear at
IC301 Pin73?
YES
Does 7.16MHz appear at
IC301 Pin69?
YES
Replace IC301.
YES
YES