Sony HCD-GRX50 / HCD-R770 / HCD-RXD7 / MHC-GRX50 / MHC-R770 / MHC-RXD7 Service Manual ▷ View online
– 13 –
3. Tape Deck Section
• The sequence during the aging mode is following as below.
• If an error occurred, stop display that step.
• If an error occurred, stop display that step.
Aging mode sequence (Tape deck section) :
Rewind the tape A and B
“TAPE A AG-1”
Shut off
FWD play the tape A
“TAPE A AG-2”
2 minutes
Fast forward the tape A
“TAPE A AG-3”
Shut off or 20 seconds
REV play the tape A
“TAPE A AG-4”
2 minutes
Rewind the tape A
“TAPE A AG-5”
Shut off
FWD play the tape B
“TAPE B AG-2”
2 minutes
Fast forward the tape B
“TAPE B AG-3”
Shut off or 20 seconds
REV play the tape B
“TAPE A AG-4”
2 minutes
Rewind the tape B
“TAPE B AG-5”
Shut off
Note:
“TAPE
*
AG-
*
” is display of each step.
– 14 –
1. Demagnetize the record/playback head with a head demagne-
tizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
3. After the adjustments, apply suitable locking compound to the
parts adjust.
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 ad-
justment should be completed before performing recording
circuit adjustment.)
justment 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 other-
wise specified.
8. Set to the DOLBY NR OFF.
9. Set to the test mode.
9. Set to the test mode.
(1) Press the
1/
u
button to turn the power ON.
(2) Select the function “TAPE A or B”.
(3) Press the button of
(3) Press the button of
p ,
[ENTER/NEXT]
, and
[DISC 3]
simultaneously, to set the tape deck test mode and blink
the indicator of disc tray number on the fluorescent indi-
cator tube.
the indicator of disc tray number on the fluorescent indi-
cator tube.
(4) To exit from the test mode, press the
1/
u
button.
• Test Tape
Record/Playback Head Azimuth Adjustment
Note:
Perform this adjustments for both decks
Procedure:
1. Mode: Playback
1. Mode: Playback
Tape
Signal
Used for
P-4-A100
10 kHz, –10 dB
Azimuth Adjustment
WS-48B
3 kHz, 0 dB
Tape Speed Adjustment
P-4-L300
315 Hz, 0 dB
Level Adjustment
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.03 – 0.08 oz • inch)
71 to 143 g • cm
(0.99 – 1.99 oz • inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
SECTION 6
ELECTRICAL ADJUSTMENTS
SECTION 5
MECHANICAL ADJUSTMENTS
Precaution
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 demagne-
tizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
Torque Measurement
Mode
FWD
Torque meter
CQ-102C
Meter reading
FWD
back tension
back tension
REV
REV
back tension
back tension
FF/REW
FWD tension
REV tension
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
0 dB=0.775 V
DECK SECTION
DECK A DECK B
set
main board
MD OUT jack (J101)
L-CH, R-CH
MD OUT jack (J101)
L-CH, R-CH
+
–
–
level meter
test tape
P-4-A100
(10 kHz, –10 dB)
P-4-A100
(10 kHz, –10 dB)
– 15 –
Screw
position
position
L-CH
peak
peak
within
1dB
1dB
Output
level
level
L-CH
peak
peak
R-CH
peak
peak
within
1dB
1dB
Screw
position
position
R-CH
peak
peak
MAIN
board
CN301
set
board
CN301
set
test tape
P-4-A100
(10 kHz, –10 dB)
P-4-A100
(10 kHz, –10 dB)
R-CH
oscilloscope
L-CH
R-CH
V
H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
main board
MD OUT jack (J101)
L-CH
MD OUT jack (J101)
L-CH
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 1dB of peak.
so that outputs match within 1dB of peak.
3. Mode: Playback
4. Repeat step 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
5. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Playback Head (Deck A).
Record/Playback/Erase Head (Deck B).
Tape Speed Adjustment
DECK B
Mode: Playback
1. Insert the WS-48B into the deck B.
2. Press the
2. Press the
( button on the deck B.
3. Press the
[HI-DUB]
button in playback mode.
Then at HIGH speed mode.
4. Adjust RV1001 on the LEAF SW board do that frequency
counter reads 6,000 ± 180 Hz.
5. Press the
[HI-DUB]
button.
Then back to NORMAL speed mode.
6. Adjust RV1002 on the LEAF SW board so that frequency
counter reads 3,000 ± 90 Hz.
Adjustment Location: LEAF SW board
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
Playback level Adjustment
DECK A DECK B
Procedure:
Mode: Playback
Mode: Playback
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
Adjustment Level:
J101 PB level: 301.5 to 338.3 mV (–8.2 to –7.2 dB) level
difference between the channels: within ±0.5 dB
difference between the channels: within ±0.5 dB
Adjustment Location: AUDIO board
forward
reverse
+
–
–
set
test tape
WS-48B
(3 kHz, 0 dB)
WS-48B
(3 kHz, 0 dB)
main board
MD OUT jack (J101)
L-CH, R-CH
MD OUT jack (J101)
L-CH, R-CH
frequency counter
+
–
–
set
test tape
P-4-L300
(315 Hz, 0 dB)
P-4-L300
(315 Hz, 0 dB)
main board
MD OUT jack (J101)
L-CH, R-CH
MD OUT jack (J101)
L-CH, R-CH
level meter
– 16 –
REC Bias Adjustment
DECK B
Procedure:
1. Mode: Record
1. Mode: Record
FUNCTION: VIDEO
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fication values as follows.
If these values are out of specification values, adjust the RV341
(L-CH) and RV441 (R-CH) on the AUDIO board to repeat
steps 1and 2.
If these values are out of specification values, adjust the RV341
(L-CH) and RV441 (R-CH) on the AUDIO board to repeat
steps 1and 2.
Specification values: Playback output of 315 Hz to playback
output of 10 kHz: ± 0.5 dB
Adjustment Location: AUDIO board
REC Level Adjustment
DECK B
Procedure:
1. Mode: Record
1. Mode: Record
FUNCTION: VIDEO
2. Mode: Playback
3. Confirm playback the signal recorded in step 1 become speci-
fication values as follows.
If these values are out of specification values, adjust the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
1 and 2.
If these values are out of specification values, adjust the RV301
(L-CH) and RV351 (R-CH) on the MAIN board to repeat steps
1 and 2.
Specification values:
J101 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
J101 PB level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
– MAIN BOARD (Conductor Side) –
– AUDIO BOARD (Component Side) –
– LEAF SW BOARD (Component Side) –
attenuator
set
main board
VIDEO (AUDIO) IN jack (J101)
L-CH, R-CH
VIDEO (AUDIO) IN jack (J101)
L-CH, R-CH
1) 315 Hz
2) 10 kHz
2) 10 kHz
50 mV (–23.8 dB)
600
Ω
blank tape
CN-123
CN-123
AF OSC
+
–
–
set
recorded
portion
portion
main board
MD OUT jack (J101)
L-CH, R-CH
MD OUT jack (J101)
L-CH, R-CH
level meter
set
main board
VIDEO (AUDIO) IN jack (J101)
L-CH, R-CH
315 Hz, 50 mV (–23.8 dB)
VIDEO (AUDIO) IN jack (J101)
L-CH, R-CH
315 Hz, 50 mV (–23.8 dB)
blank tape
CS-123
CS-123
600
Ω
attenuator
AF OSC
+
–
–
set
recorded
portion
portion
main board
MD OUT jack (J101)
L-CH, R-CH
MD OUT jack (J101)
L-CH, R-CH
level meter
RV301
L
RV351
R
IC301
REC LEVEL
J101
VIDEO (AUDIO) IN
(L/R)
MD OUT
(L/R)
RV401
RV301
RV341
RV311
RV411
IC602
CN601
L
R
R L
RV441
PB LEVEL
– DECK B –
REC BIAS
L
R
PB LEVEL
– DECK A –
TAPE SPEED
RV1002
RV1001
(NORMAL) (HIGH)
CN1001
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