Sony HCD-VX77 Service Manual page 19

DECK B
REC Bias Adjustment
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjustment,
when the tape is rewound after recording, the "REC memory mode"
which rewinds only the recorded portion and playback is set.
This "REC memory mode" is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO.
(If do not operation of stopped from recording complete, and rotette
of shuttle knob then rewind to recording start position.)
1. Press MD/VIDEO button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press REC PAUSE/START button, press REC PAUSE/
START button, then recording start.
4. Mode: Record
MD/VIDEO (AUDIO) IN

1) 315 Hz

2) 10 kHz

AF OSC
600 Ω
attenuator
5. Mode: Playback
recorded
portion
set
CN301 (Pin 3 : L-CH)
6. Confirm playback the signal recorded in step 3 become
adjustable level as follows.
If these levels do not adjustable level, adjustment the RV304
(L-CH) and RV354 (R-CH) on the AUDIO board to repeat steps
4 and 5.
Adjustable level: Playback output of 315 Hz to playback output
of 10 kHz: ±1.0 dB
Adjustment Location: MAIN board
DECK B
REC Level Adjustment
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjustment,
when the tape is rewound after recording, the "REC memory mode"
which rewinds only the recorded portion and playback is set.
This "REC memory mode" is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO.
(If do not operation of stopped from recording complete, and rotate
of shuttle knob then rewind to recording start position.)
1. Press MD/VIDEO button to select VIDEO. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B.
3. After press REC PAUSE/START button, press REC PAUSE/
START button, then recording start.
50 mV (–23.8 dB)
blank tape
CN-123
set
level meter
+
–
(Pin 1 : R-CH)
4. Mode: Record
MD/VIDEO (AUDIO) IN
315 Hz, 50 mV (–23.8 dB)
AF OSC
600 Ω
attenuator
5. Mode: Playback
recorded
portion
set
CN301 (Pin 3 : L-CH)
6. Confirm playback the signal recorded in step 3 become
adjustable level as follows.
If these levels do not adjustable level, adjustment the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
4 and 5.
Adjustable level:
CN301 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
[MAIN BOARD] (Component Side)
T601
RV611
PB LEVEL (R)
(A)
PB LEVEL (R)
(B)
REC LEVEL (R)
(B)
REC LEVEL (L)
(A)
[LEAF SW BOARD] (Component Side)
TAPE SPEED
(NORMAL) (HIGH)
RV1002
RV1001
blank tape
CS-123
set
level meter
+
–
(Pin 1 : R-CH)
REC LEVEL (L)
(B)
PB LEVEL (L)
(A)
CN304
CN301
3 1
RV301
RV302
CN302
RV352
RV353
RV303
RV351
CN303
PB LEVEL (L)
(B)
RV304
RV354
REC LEVEL (R)
(A)
CN1001
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