Aiwa HV-FX7800 Service Manual page 65

ELECTRICAL TROUBLESHOOTING -13/17
5. Tuner/IF circuit
(1) No picture on the TV screen
No picture on the
TV screen
Does the Video signal at
the TU701 Pin24?
Does Sync appear at
IC501 Pin39?
Check the signal flow from
IC501 Pin19 to JK901
Pin19.
YES
NO
YES
NO
YES
Is +30VT applied to
TU701 Pin 16?
YES
Is +5VT applied to
TU701 Pin 13?
YES
Does the Clock signal
appear at TU701 Pin 11?
YES
Does the data signal
appear at TU701 Pin 12?
YES
Replace Tuner
Check the signal flow
from TU701 Pin 24 to
IC301 Pin 38.
-65-
NO
Check 33VT line.
NO
Check 5VT line.
NO
Check the lIC Clock
signal of µ-com Pin 59.
NO
Check the lIC Data signal
of µ-com Pin 60.