Sony HCD-H991AV / MHC-991AV / MHC-G99AV Service Manual ▷ View online
— 9 —
3-4. JOG BOARD, PANEL BOARD
1 Knob (VOL) * Note
2 Knob (JOG) * Note
3 Nut
4 Nut
6 Claw
7 Two claws
8 Two claws
5 Seven screws
(+BVTP2.6x8)
9 JOG board
0 Panel board
* Note (Removal of knob)
It will be easy to remove if you push
lightly from the hole of the JOG board
with some screwdrivers or etc.
lightly from the hole of the JOG board
with some screwdrivers or etc.
3-3. TC MECHANISM DECK
1 Push the EJECT button.
3 Screw (+BVTP3x8)
4 Wire
6 Two screws
(+BVTP2.6x8)
7 TC Mechanism deck.
8 EJECT knob
0 HP/MIC board
2 Cassette lid (A), (B)
9 EJECT knob
5 Two screws
(+BVTP2.6x8)
— 10 —
claw A
claw B
Note: When installing the Disc tray, pull around the flat type wire to
pass through the claw A and claw B, as shown in the figure.
3-5. DISC TRAY
(Perform after removing the front panel.)
1 Turn the cam to the direction
of arrow.
2 Pull-out the disc tray.
5 Remove the disc tray.
5 Remove the disc tray.
4 Two claws
3 Flat type wire (8 core)
— 11 —
Precaution
1. Clean the following parts with a denatured alcohol-moistened
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads
pinch rollers
erase head
rubber belts
capstan
idlers
2. Demagnetize the record/playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power supply
voltage unless otherwise noted.
Torque Measurement
SECTION 5
ELECTRICAL ADJUSTMENTS
DECK SECTION
0 dB=0.775V
1. Demagnetize the record/playback head with a head damagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjusted.
4. The adjustments should be performed with the rated power supply
voltage unless otherwise noted.
5. The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit
adjustment.)
should be completed before performing recording circuit
adjustment.)
6. The adjustments should be performed for both L-CH and R-CH.
7. Switches and controls should be set as follows unless otherwise
7. Switches and controls should be set as follows unless otherwise
specified.
DOLBY NR switch: OFF
2 to 6 g • cm
(0.02 - 0.08 oz • inch)
61 to 143 g • cm
(0.85 - 1.99 oz • inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
SECTION 4
MECHANICAL ADJUSTMENTS
Torque
Torque meter
Meter reading
FWD
FWD
back tension
back tension
REV
REV
back tension
back tension
FF/REW
FWD tension
REV tension
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
36 to 61 g • cm
(0.5 - 0.84 oz • inch)
2 to 6 g • cm
(0.02 - 0.08 oz • inch)
36 to 61 g • cm
(0.5 - 0.84 oz • inch)
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
1. Mode : Playback
test tape
P-4-A100
(10kHz, –10dB)
P-4-A100
(10kHz, –10dB)
main board
CN403
Pin 3 (L-CH)
Pin 1 (R-CH)
CN403
Pin 3 (L-CH)
Pin 1 (R-CH)
main board
CN403
Pin 2 (GND)
CN403
Pin 2 (GND)
level meter
+
–
Signal
Used for
10 kHz, –10 dB
3 kHz, 0 dB
315 Hz, 0 dB
Azimuth Adjustment
Tape Speed Adjustment
Level Adjustment
Tape
P-4-A100
WS-48B
P-4-L300
set
— 12 —
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw so
that outputs match within 1 dB of peak.
that outputs match within 1 dB of peak.
L-CH
peak
peak
R-CH
peak
peak
screw
position
position
output
level
level
within
1dB
1dB
within 1dB
L-CH
peak
peak
screw
position
position
R-CH
peak
peak
3. Mode: Playback
Tape Speed Adjustment (Deck A)
Note: Start the Tape Speed adjustment as below after setting the
test mode.
The tape speed can be changed with the HIGH SPEED
DUBBING button during the test mode.
The tape speed can be changed with the HIGH SPEED
DUBBING button during the test mode.
Method :
1. Turn the power switch on.
2. Press the DISPLAY/DEMO button, MENU 1 button and
1. Turn the power switch on.
2. Press the DISPLAY/DEMO button, MENU 1 button and
TUNER/BAND button simultaneously.
Procedure :
Mode: Playback
Mode: Playback
frequency counter
+
–
–
main board
CN403 Pin 3 (L-CH)
CN403 Pin 3 (L-CH)
Pin 1 (R-CH)
test tape WS-48B
(3kHz, 0dB)
(3kHz, 0dB)
1. Insert the WS-48B into the deck A to playback.
2. Press the HIGH SPEED DUBBING button. Then at HIGH
2. Press the HIGH SPEED DUBBING button. Then at HIGH
SPEED mode.
3. Adjust the RV652 on the MD board so that the frequency
counter reading becomes 6,000
±
30 Hz.
4. Press the HIGH SPEED DUBBING button again to be set the
NORMAL SPEED mode.
5. Set to the playback mode.
6. Adjust the RV651 on the MD board so that the frequency
6. Adjust the RV651 on the MD board so that the frequency
counter reading becomes 3,000
±
15 Hz.
Frequency difference between deck A and deck B the beginning
of the tape should be within
of the tape should be within
±
1.5%.
Adjustment Location: MD board
Playback Level Adjustment (Deck A, Deck B)
Procedure:
Mode: Playback
set
main board
CN403 Pin 3 (L-CH)
CN403 Pin 3 (L-CH)
Pin 1 (R-CH)
level meter
Deck A is RV311 (L-CH) and RV411 (R-CH), deck B is RV301
(L-CH) and RV401 (R-CH)
so that adjustment within the following adjustment level.
(L-CH) and RV401 (R-CH)
so that adjustment within the following adjustment level.
Adjustment level:
CN403 playback level: 301.5 to 338.3 mV (–8.2 to –7.2 dB)
level difference between the channels: within
level difference between the channels: within
±
0.5 dB
Adjustment Location: MD board
test tape P-4-L300
(315Hz, 0dB)
(315Hz, 0dB)
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location: Playback Head (Deck A)
Record/Playback/Erase Head (Deck B)
Waveform of oscilloscope
45˚
90˚
135˚
180˚
wrong
good
in phase
main board
CN403
Pin 3 (L-CH)
CN403
Pin 3 (L-CH)
Pin 2 (GND)
L
R
oscilloscope
Pin 1 (R-CH)
test tape
P-4-A100
(10kHz, –10dB)
P-4-A100
(10kHz, –10dB)
set
Adjustment screw
FWD side
REV side
set
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