Aiwa HV-FX7800 Service Manual page 63

ELECTRICAL TROUBLESHOOTING -11/17
3. Y/C CIRCUIT
(3) When the C(Color) signal doesn't appear on the screen in PB Mode,
Is 5V applied to the IC301
Pins 16, 40, 55, 58, 87?
Is the Color Rotary signal
applied to the IC301
Pin 10?
Is Color Rotary "H"
about 1.6V?
Does the Color signal
appear at the IC301
Pin 71 ?
Replace the IC301.
NO
YES
NO
YES
NO
YES
NO
YES
Check the line of the 5.2V
Line. (Power Circuit)
Check the Color Rotary
Circuit. (IC501 pin 99)
Check the Color Rotary
level.
(Check the R303)
Does the X301(4.43MHZ)
oscillate?
Does the Color signal
appear at the IC301 Pin 61?
Check the circuit of the
IC301 35, 62.
-63-
NO
Replace the X301.
NO
Check the Color Pass.
(Check the Q304)
YES
Replace the IC301.