Sony HCD-MG510AV / MHC-MG510AV Service Manual ▷ View online
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
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.
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
parts adjusted.
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
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 AMP board
FRONT SPEAKER terminal (J501)
L-CH
FRONT SPEAKER terminal (J501)
L-CH
+
–
–
set
test tape
WS-48A
(3 kHz, 0 dB)
WS-48A
(3 kHz, 0 dB)
MAIN AMP board
FRONT SPEAKER terminal (J501)
L-CH, R-CH
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)
1. Mode: Playback (FWD)
DECK A DECK B
set
MAIN AMP board
FRONT SPEAKER terminal (J501)
L-CH, R-CH
FRONT SPEAKER terminal (J501)
L-CH, R-CH
+
–
–
level meter
test tape
P-4-A100
(10 kHz, – 10 dB)
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
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.
1.
Connect an oscilloscope to test point TP (FE) and TP (VC) on
the CD board.
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)
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
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.
1.
Connect an oscilloscope to test point TP (RFDC) and TP (VC)
on the CD board.
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.
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
TIME/DIV: 500 ns
level: 1.15
±
0.35 Vp-p
RFDC signal waveform
Checking Location: CD board
RFAC Level Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP (RFAC) and TP (VC)
on the CD board.
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.
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
TIME/DIV: 500 ns
level: 1.35
±
0.4 Vp-p
19
HCD-MG510AV
Ver 1.1
E-F Balance Check
Connection:
Procedure:
1.
1.
Connect an oscilloscpe to test point TP (TE) and TP (VC) on
the CD board.
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
(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.
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
the waveform
A (DC
voltage)
0V
Tracking servo
Sled servo
ON
C (DC
voltage)
voltage)
Tracking servo
Sled servo
OFF
Checking Location:
– CD BOARD (Conductor Side) –
TP (VC)
TP (FE)
TP (TE)
TP
(RFDC)
TP
(RFAC)
IC103
IC101
20
HCD-MG510AV
SENSOR SECTION
Disc Sensor Level Adjustment
Procedure:
1.
1.
Connect an oscilloscope to TP (DISC SENSOR) and TP (GND)
on the MAIN board.
on the MAIN board.
2.
Turn the power on.
3.
In the no disc status, adjust RV301 on the MAIN board so that
the waveform of oscilloscope becomes as below. And check
the peak to peak level is more than 4 Vp-p.
the waveform of oscilloscope becomes as below. And check
the peak to peak level is more than 4 Vp-p.
4.
Insert a disc into the disc slot No. 58.
5.
Check that the waveform of oscilloscope as below. And adjust
RV301 on the MAIN board so that the peak to peak level
becomes less than 0.5 Vp-p besides becomes as little as possible.
RV301 on the MAIN board so that the peak to peak level
becomes less than 0.5 Vp-p besides becomes as little as possible.
6.
Check that the waveform and peak to peak level satisfy
specification of step 4. If it is wrong, repeat from step 4 until
satisfy.
specification of step 4. If it is wrong, repeat from step 4 until
satisfy.
Adjustment Location:
Waveform when no disc
,
turn the RV301
NG
OK
more than 4 Vp-p
Waveform when disc in
less than 0.5 Vp-p
[MAIN BOARD] (CONDUCTOR SIDE)
RV301
Disc Sensor Level
Adjustment
TP (GND)
TP (DISC SENSOR)
Ver 1.1
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