Sony UDA-1 Service Manual page 18

UDA-1
4. When sound is not outputted
START
The volume knob is turned to
Check that the
NG
the position at ten o'clock.
sound from the
And check that voltage of the
LINE IN input is
following is about 0.3 V.
outputted of
DCDC board: CL193 or
speaker.
CN190 pin 3 (VR signal)
OK
Check that the two harnesses
are correctly inserted in CN212
on the AMP board and CN401
on the DAC board, CN205 on
the AMP board and CN403 on
the DAC board.
Check that the fuses (F200,
F201) on the AMP board are
not damaged.
Check that voltage of the
following is about 16 V.
AMP board: CL272
Check that voltage of the
following is about 7 V.
AMP board:
CL265 or IC203 pin 2
Check that voltage of the
following is about –7 V.
AMP board:
CL266 or IC204 pin 2
Check that the pin jack (J400
on the DAC board) terminal
is normal.
– Continued on
page 20 –
18
OK
NG
OK
NG
OK
OK
NG
OK
NG
OK
NG
OK
– Continued on
page 19 –
Reinsert the harness.
Repair the harness.
Exchange the fuses (F200,
F201) on the AMP board.
Check that between the 7 V
line and the ground does not
short circuit.
open
Check that voltage of the
following is about 16 V.
AMP board: CL214
Check that between the –7 V
line and the ground does not
short circuit.
open
Check that voltage of the
following is about –16 V.
AMP board: CL222
Exchange the J400 on the
DAC board.
Exchange the AMP board.
short
Next, exchange the DAC
board.
Check the following parts and
NG
the surrounding circuit.
AMP board:
D202, D204, D207, D209
Check the T001 (main power
transformer)
Exchange the AMP board.
short
Next, exchange the DAC
board.
Check the following parts and
NG
the surrounding circuit.
AMP board:
D202, D204, D207, D209
Check the T001 (main power
transformer)