Sony CAS-1, Service Manual

Page: 30 / 98

CAS-1
30
2. Sound is not outputted from the headphone
Sound is not outputted from the
headphone.
End
Yes
The area surrounding circuit of
headphone
is supplied with the voltage
of AHP+7 V.
Yes
Relay (RY400) on the MAIN board is
supplied with the voltage of AHP+7 V.
Switching sound is heard from the relay
(RY400) on the MAIN board, when the
headphone is plugged or unplugged.
No
Check the IC004 and coil (L007) on
the AMP board, and replace the
parts of area surrounding circuit of
IC005 on the AMP board.
No
Replace the parts of area
surrounding circuit of part which is
not specified voltage.
No
Yes
The voltage of the following is +9.5 V.
AMP board: IC004 pin 8, coil (L007)
The voltage of the following is +7 V.
AMP board: IC005 pin 3
No
The area surrounding circuit of
headphone
is supplied with the voltage
of AHP – 7 V .
Yes
No
The area surrounding circuit of
headphone
is supplied with the voltage
of DAC+5 V.
Yes
Yes
Yes
Yes
Yes
Replace the parts of area surrounding
circuit of IC656, IC657 on the MAIN
board.
No
The signal of DAC-LRCK, DAC-DATA,
DAC-BCK is inputted to the IC401 pin
4, 5, 6 on the MAIN board.
Replace the parts of area surrounding
circuit of IC211 on the AMP board.
No
The signal of DAC-MCK is inputted to
the IC401 pin 7 on the MAIN board.
Replace the parts of area surrounding
circuit of IC401, IC404, IC405, IC406 on
the MAIN board.
No
The audio signal is inputted to the IC407
pin 1, 32 on the MAIN board.
Replace the parts of area surrounding
circuit of IC407 on the MAIN board.
No
The audio signal is outputted from the
IC407 pin 8, 25 on the MAIN board.
Replace the parts of area surrounding
circuit of IC408, IC409 on the MAIN
board.
No
The audio signal is outputted from the
resistor (R475, R476) on the MAIN
board.
Yes
Yes
Yes
Yes
Replace the parts of area
surrounding circuit of part which is
not specified voltage.
No
The voltage of the following is – 9.5 V.
AMP board: IC001 pin 6, coil (L008)
The voltage of the following is
– 7 V.
AMP board: IC006 pin 3
Yes
No
Replace the IC403 on the MAIN
board and parts of area surrounding
circuit.
No
The voltage of the following is +5 V.
MAIN board: IC403 pin 4
Yes
The area surrounding circuit of
headphone
is supplied with the voltage
of DAC+3.3 V.
Yes
No
Replace the IC402 on the MAIN
board and parts of area surrounding
circuit.
No
The voltage of the following is +3.3 V.
MAIN board: IC402 pin 4
Yes
Yes
Yes
Yes
Yes
Replace the parts of area surrounding
circuit of relay (RY400) on the MAIN
board.
Yes
Yes
Yes
Yes
Yes
Yes
Note: Perform the operation check in the dotted line frame in the state of connecting the
headphone to this unit.
(Except for parts replacement and so on)