DOWNLOAD Sony HCD-MG510AV / MHC-MG510AV Service Manual ↓ Size: 7.7 MB | Pages: 73 in PDF or view online for FREE

Model
HCD-MG510AV MHC-MG510AV
Pages
73
Size
7.7 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
hcd-mg510av-mhc-mg510av.pdf
Date

Sony HCD-MG510AV / MHC-MG510AV Service Manual ▷ View online

16
HCD-MG510AV
SECTION  5
MECHANICAL ADJUSTMENTS
 TAPE MECHANISM DECK SECTION
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
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
Torque Measurement
2.94 mN • m to 7.84 mN • m
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
0.14 mN • m to 0.59 mN • m
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
2.94 mN • m to 7.84 mN • m
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
0.14 mN • m to 0.59 mN • m
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
6.86 mN • m to 17.64 mN • m
71 to 143 g • cm
(0.98 – 1.99 oz • inch)
more than 0.98 N • m
100 g or more
(3.53 oz or more)
more than 0.98 N • m
100 g or more
(3.53 oz or more)
Mode
Torque meter
CQ-102C
CQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
Meter reading
FWD
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension
Ver 1.1
SECTION  6
ELECTRICAL  ADJUSTMENTS
Precaution
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
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.)
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.
• Test Tape
Tape
Signal
Used for
P-4-A100
10 kHz, – 10 dB
Azimuth Adjustment
WS-48A
3 kHz, 0 dB
Tape Speed Check
0 dB = 0.775 V
DECK  SECTION
17
HCD-MG510AV
Tape Speed Check
DECK B
Mode: Playback
1. Insert the WS-48A into the deck B.
2. Press the nN button on the deck B.
3. Confirm that the frequency counter reads 3,000 
±
 60 Hz.
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48A)
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.
3. Mode: Playback
4. Repeat step 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
parts adjusted.
Screw
position
L-CH
peak
within
1dB
Output
level
L-CH
peak
R-CH
peak
within
1dB
Screw
position
R-CH
peak
set
test tape
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 AMP board
FRONT SPEAKER terminal (J501)
L-CH
+
set
test tape
WS-48A 
(3 kHz, 0 dB)
MAIN AMP board
FRONT SPEAKER terminal (J501)
L-CH, R-CH
frequency counter
Record/Playback Head Azimuth Adjustment
Note:
 Perform this adjustments for both decks
Procedure:
1. Mode: Playback (FWD)
DECK A      DECK B
set
MAIN AMP board
FRONT SPEAKER terminal (J501)
L-CH, R-CH
+
level meter
test tape
P-4-A100
(10 kHz, – 10 dB)
Adjustment Location: Playback Head (Deck A).
Record/Playback/Erase Head (Deck B).
reverse
forward
Ver 1.1
18
HCD-MG510AV
Ver 1.1
CD  SECTION
Note:
1. CD Block is basically designed to operate without adjustment. There-
fore, check each item in order given.
2. Use PATD-012 disc (4-225-203-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10MW impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
S Curve Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP (FE) and TP (VC) on
the CD board.
2.
Turn the power on.
3.
Put the disc (PATD-012) in and turned power switch on again
and actuate the focus search. (actuate the focus search when
disc table is moving in and out)
4.
Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2 
±
 1
Vp-p.
S-curve waveform
Note:
 • Try to measure several times to make sure than the ratio of A : B
or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Checking Location: CD board
RFDC Level Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP (RFDC) and TP (VC)
on the CD board.
2.
Turn the power on.
3.
Put the disc (PATD-012) in to playback the number two track.
4.
Confirm that oscilloscope waveform is clear and check the level
of between RFDC top and VC is correct or not.
Note:
A clear RFDC signal waveform means that the shape “
” can be
clearly distinguished at the center of the waveform.
+
CD board
TP (FE)
TP (VC)
oscilloscope
A
B
symmetry
within 2 
±
 1 Vp-p
+
CD board
TP (RFDC)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns 
level: 1.15 
±
 0.35 Vp-p
       RFDC signal waveform
Checking Location: CD board
RFAC Level Check
Connection:
Procedure:
1.
Connect an oscilloscope to test point TP (RFAC) and TP (VC)
on the CD board.
2.
Turn the power on.
3.
Put the disc (PATD-012) in to playback the number two track.
4.
Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
Note:
A clear RFAC signal waveform means that the shape “
” can be
clearly distinguished at the center of the waveform.
       RFAC signal waveform
Checking Location: CD board
+
CD board
TP (RFAC)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns 
level: 1.35 
±
 0.4 Vp-p
19
HCD-MG510AV
Ver 1.1
E-F Balance Check
Connection:
Procedure:
1.
Connect an oscilloscpe to test point TP (TE) and TP (VC) on
the CD board.
2.
Turn the power on.
3.
Put the disc (PATD-012) in to playback the number two track.
4.
Press the 
[REPEAT]
 button.  (The tracking servo and the
sledding servo are turned OFF)
5.
Check the level B of the oscilliscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than 
±
 22%
Traverse Waveform
6.
Press the 
[REPEAT]
 button. (The tracking servo and sledding
servo are turned ON)
Confirm the C (DC voltage) is almost equal to the A (DC
voltage) is step 5.
Traverse Waveform
Checking Location: CD board
+
CD board
TP (TE)
TP (VC)
oscilloscope
0V
B
level: 1.15 
±
 0.5 Vp-p
Center of 
the waveform
A (DC 
voltage)
0V
Tracking servo
Sled servo
ON
C (DC 
voltage)
Tracking servo
Sled servo
OFF
Checking Location:
– CD BOARD (Conductor Side) –
TP (VC)
TP (FE)
TP (TE)
TP
 (RFDC)
TP
 (RFAC)
IC103
IC101
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