Hitachi DV-PF73U Service Manual page 31

FLOW CHART NO.11
Hi-Fi E-E audio does not operate normally.
Is each signal supplied to each pin of IC451 as below?
Front input terminal
Rear input terminal
Tuner audio signal
Is the 5V voltage supplied to Pins(5,15,32,36,46) of
IC451, or the 9V voltage supplied to Pins(3,54) of IC451?
Is the serial data and the clock signal supplied to
Pins(37,38) of IC451?
Is the "L" pulse inputted into the Pin(49) of IC451?
Is the sub carrier signal (3.58 MHz) inputted to
Pin(51) of IC451?
Is the audio signal outputted to Pins(78,80) of
IC451?
Is the audio signal inputted into Pins(3,13) of
IC751?
Is the audio signal outputted to Pins(4,14) of
IC751?
Check the line between Pins(4,14) of IC751 and
the audio output terminal (JK751), and service it if
detective.
Replace IC751.
3-12
L-ch R-ch
Pin(9) Pin(71)
Pin(7) Pin(69)
Pin(57)
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Check the peripheral circuit of the front input
terminal and service it if detective.
Check the peripheral circuit of the rear input
No
terminal and service it if detective.
No
No
Is the SIF signal outputted from Pin(15) of the tuner?
Check the line between Pin(57)
of IC451 and Pin(15) of tuner,
and service it if detective.
No
Check the circuit of AL+5V, P-ON+5V and
P-ON+9V, and service it if detective.
No
Check the line between Pins(37,38) of IC451 and
Pins(12,13) of IC501, and service it if detective.
No
Check the line between Pin(49) of IC451 and
Pin(7) of IC501, and service it if detective.
No
Check the line between the emitter of Q302 and
Pin(51) of IC451, and service it if detective.
No
Replace IC451.
No
Check the line between Pins(78,80) of IC451 and
Pins(3,13) of IC751, and service it if detective.
Is approximately 6.8V voltage supplied to Pin(16)
No
of IC751, or approximately -8V voltage supplied to
Pin(7) of IC751?
Check the AL+12V line (R779, D702) and the
Yes
AL-30V line (R777,R778), and service it if detective.
Yes
Is the "H" pulse inputted into the Pins(9,10,11) of
IC751?
Check Q760 and the OUTPUT SELECT line, and
service it if detective.
Yes
Replace the
tuner.
No
No
No