Zenith XBV443 Service Manual page 22

3. Y/C CIRCUIT
(3) When the C(Color) signal doesn't appear on the screen in PB Mode,
Is 5.2VT/5.3VA applied to the
IC301 Pins 22, 47, 60, 84.
YES
Is the Color signal applied
to the IC301 Pin 57?
YES
Replace the IC301.
NO
Is normal the X301
NO
(3.58MHZ) of oscillation
Frequency?
Does the Color signal
appear at the IC301 Pin55?
Replace the IC301.
3-13
Check the SW 5V, 5.3V
Line. (Power Circuit)
NO
NO
YES
Replace the X301.
Check the Color Pass.