Sony HCD-GX40 / MHC-GX40 Service Manual ▷ View online
17
HCD-GX40
SECTION 4
ELECTRICAL ADJUSTMENTS
FM Tuned Level Adjustment
Procedure:
1.
1.
Supply a 98 MHz signal at 28 dB from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Adjust RV101 to the point (moment) when the TUNED
indicator will change from going off to going on.
indicator will change from going off to going on.
Adjustment Location: MAIN board
Null Adjustment
Procedure:
1.
1.
Supply a 98 MHz signal at 60 dB from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Measure voltage between pin 21 and pin 23 of IC 101. Adjust
T101 until the voltage becomes 0 V.
T101 until the voltage becomes 0 V.
Adjustment Location: MAIN board
FM RF Signal generator
75
Ω
coaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 30 dB (at 75
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 30 dB (at 75
Ω
open)
FM ANTENNA terminal
(JK103)
(JK103)
set
FM RF Signal generator
75
Ω
coaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75
Ω
open)
FM ANTENNA terminal
(JK103)
(JK103)
set
T101: NULL
IFT101: AM IF
RV101:
FM TUNED LEVEL
FM TUNED LEVEL
TUNER SECTION
AM RF Signal generator
30% amplitude
modulation by
400Hz signal
output level : as low as possible
modulation by
400Hz signal
output level : as low as possible
AM ANTENNA terminal
(JK103)
(JK103)
set
AM IF Adjustment
Procedure:
1.
1.
Set the frequency of the AM RF signal generator to 1000 kHz
(at 10 kHz step) or 999 kHz (at 9 kHz step).
(at 10 kHz step) or 999 kHz (at 9 kHz step).
2.
Tune the set to AM 1000 kHz (at 10 kHz step) or 999 kHz (at 9
kHz step).
kHz step).
3.
Adjust IFT101 so that the reading on level meter becomes in
maximum.
maximum.
headphones jack (JK691)
level meter
set
16
Ω
[MAIN BOARD] Component side
18
HCD-GX40
CN731
TP731:
TP connected to pin
TP connected to pin
q;
(IC751)
IC751
CN733
IC731
Adjustment Location: CD board
[CD BOARD] (Component Side)
CD SECTION
RF Level Check
Procedure :
1. Connect oscilloscope to pin q; (IC751).
2. Turned Power switch on.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal
1. Connect oscilloscope to pin q; (IC751).
2. Turned Power switch on.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
IC751 pin
q;
GND
CD board
oscilloscope
Note :
Clear RF signal waveform means that the shape “
◊
” can be clearly
distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 1.4 to 2.1 Vp-p
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
3. Use an oscilloscope with more than 10M
Ω
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.
following checks.
19
19
HCD-GX40
SECTION 5
DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
f
: internal component.
•
C
: panel designation.
Note on Printed Wiring Boards:
• X
: parts extracted from the component side.
• b
: Pattern from the side which enables seeing.
• Indication of transistor.
Note:
The components identi-
fied by mark
The components identi-
fied by mark
0
or dotted
line with mark
0
are criti-
cal for safety.
Replace only with part
number specified.
Replace only with part
number specified.
Note:
Les composants identifiés par
une marque
Les composants identifiés par
une marque
0
sont critiques
pour la sécurité.
Ne les remplacer que par une
piéce portant le numéro
spécifié.
Ne les remplacer que par une
piéce portant le numéro
spécifié.
•
A
: B+ Line.
•
B
: B– Line.
•
H
: adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
no mark : FM
<
tion tolerances.
no mark : FM
<
> : CD
[
] : TAPE
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F
: FM
E
: PB (DECK A)
d
: PB (DECK B)
G
: REC (DECK B)
J
: CD
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
C
B
These are omitted.
E
Q
B
These are omitted.
C
E
Q
5-1. Circuit Boards Location
• Waveforms
KEY BOARD board
PANEL board
SUB TRANS board
MAIN board
CD board
SENSOR board
TRANS board
VIDEO OUT board
POWER board
DRIVER board
MOTOR board
SPDL board
ADDRESS SENSOR board
REM board
AMPLIFIER
board
5
Q209 Collector
(TAPE REC mode)
(TAPE REC mode)
2
IC601
qd
(XT2)
1
IC751
rf
(XOUT)
4
IC102
ws
(XOUT)
2 V/DIV, 100 ns/DIV
5 V/DIV, 10 s/DIV
2 V/DIV, 10 s/DIV
2 V/DIV, 20 ns/DIV
3
IC601
qh
(CF2)
2 V/DIV, 40 ns/DIV
5.2 Vp-p
5.6 Vp-p
59 ns
222 ns
30.5 s
4.9 Vp-p
100 ns
5.0 Vp-p
13.5 Vp-p
17 s
20
20
HCD-GX40
5-2. Block Diagrams
CD Section
: CD
• Signal Path
• R-CH is omitted due to same as L-CH
OPTICAL PICK-UP
BLOCK
(KSM-213D)
LD
DRIVER
Q731
+5V
LD
GND
FOCUS
COIL
F+
F
T+
T
TRACKING
COIL
IC781
FCS/TRK COIL,
SL/SP MOTOR
SL/SP MOTOR
DRIVER
SLED/SPINDLE SERVO,
RF AMP
IC731
1
25
2
27
26
VR
PD
11
12
18
17
3
9
20
7
MUTE
CH1OUT-A
CH1IN-A
CH1IN-B
CH4IN-A
CH2IN-B
CH3IN-B
CH1OUT-B
CH4OUT-A
CH4OUT-B
CH2OUT-B
CH2OUT-A
CH3OUT-B
CH3OUT-A
M
M
(SLED)
(SPINDLE)
S01
(LIMIT)
41
RF SM
VR
58
VCC
VC
A
B
C
D
E
F
DETECTOR
FOCUS/TRACKING/
FIN 1
FIN 2
E
3
F
4
LDD
62
LDS
63
FD
16
TO
15
SLD
29
SPD
27
52
DAT
50
CLK
51
CL
53
CE
34
TGL
54
DRF
39
CV-
40
CV+
Q775
30
SL-
31
SL+
35
TOFF
44
SLI
49
DEF
36
TES
37
HFL
33
JP+
32
JP-
DIGITAL SIGNAL
PROCESSOR
IC751
EFMI
10
EFMO
9
DEF
1
TES
16
HFL
15
JP+
19
JP-
20
COIN
56
4.2M
61
CQCK
57
RWC
54
TGL
18
TOFF
17
SHUTER IN/OUT
28
CLV+
12
CLV-
13
LIMIT SW
27
53
WRQ
55
SQOUT
3
PDO
45
XIN
44
XOUT
X701
16.9344MHz
37
LCHO
40
RCHO
R CH
58
RES
CD CHANGER
CONTROL
IC601 (1/3)
69
99
WRQ
SQOUT
COIN
98
CD RESET
76
SQCK
100
CD RWC
6
CD DRF
68
CD SLED(+)
74
CD SLED(-)
75
D732
IC701
MOTOR
DRIVER
DRIVER
9
7
M
4
2
71
CD NUMBER SENSOR
70
CD BUSY
(PIC UP/DOWN)SW
80
CD OPEN
TABLE
SENSOR
IC711
S701
A
MAIN
SECTION
CD-L
2
1
38
SLOF
RF GAIN
24
4
D_MUTE
26
Q774
MUTE
Q771
73 CD MUTE
67
CD CLOSE
4
CD MOTOR+
5
CD MOTOR-
M721
(TURN)
S711
(UP/DOWN)
(OPEN/CLOSE)
Ver 1.2 2003.11
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