HCD-GX40, MHC-GX40 — Sony Audio Service Manual (repair manual). Page 16

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16
HCD-GX40
[MC Test  Mode]
• This mode is used to test the function of the equalizer.
Procedure:
1. Press  ?/1  button to turn the set ON.
2. To enter the test mode, press the three buttons  x ,  GAME EQ
and  DISC 3  simultaneously.
3. Press the  MOVIE EQ  button.
The function of the equalizer is set to “MIN”.
4. Press the  MUSIC EQ  button.
The function of the equalizer is set to “MAX”.
5. Press the  P.FILE  button.
The function of the equalizer is set to “FLAT”.
6. To exit from this mode, press  ?/1  button to turn the set OFF.
[CD Ship Mode (No Memory Clear) ]
• This mode moves the pickup to the position durable to vibra-
tion. Use this mode when returning the set to the customer after
repair.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select the function “CD”.
3. Press  ?/1  button to turn the set OFF.
4. Press  CD  button and  ?/1   button simultaneously.
5. The "STANDBY" display blinks instantaneously, and the CD
ship mode is set.
[Disc Tray  Lock]
Procedure:
1.
Press the  ?/1  button to turn the set on.
2.
Press two buttons of  x  and  OPEN/CLOSE  simultaneously
for five seconds.
3.
The message “LOCKED” is displayed and the tray is locked.
(Even if exiting from this mode, the tray is still locked.)
4.
Press two buttons of  x  and  OPEN/CLOSE  simultaneously
for five seconds again.
5.
The message “UNLOCKED” is displayed and the tray is
unlocked.
6.
To exit from this mode, press the  ?/1  button to turn the set
off.
[GC Test  Mode]
• All fluorecent segments and LEDs are tested.
• Keyboard check.
Procedure:
1. Press  ?/1  button to turn the set ON.
2. To enter the test mode, press the three buttons  x ,  GAME EQ
and  DISC 2  simultaneously.
3. All segments and LEDs (without STANDBY LED) are turned
on.
4. Press  GAME EQ  and  DISC 2  buttons simultaneously, and the
key check mode is activated.
5. The message “KEY 0 0 0 0” is displayed.
Each time a button is pressed, the key code number is displayed.
6. Press  GAME EQ  and  DISC 2  buttons simultaneously, and the
key count mode is activated.
7. The message “KEYCNT 0 1” is displayed.
Each time a button is pressed, “KEYCNT 0 1” value increased.
However, once a button is pressed, it is no longer taken into
account.
8. Press  GAME EQ  and  DISC 2  buttons simultaneously, and the
head phone detect mode is activated.
9. The message “H_P OFF” is displayed when a headphone jack
is not inserted.
“H_P ON ” is displayed when a headphone jack is inserted.
10. Press  GAME EQ  and  DISC 2  buttons simultaneously, and the
volume control detect mode is activated.
11. The message “VOLUME FLAT” is displayed.
“VOLUME UP” is displayed if rotating VOLUME knob
clockwise, or “VOLUME DOWN” is displayed if rotating
counterclockwise.
12. To exit from the GC test mode after the volume control detect
mode, press  GAME EQ  and  DISC 2  buttons simultaneously.
[Version and Destination Display Mode]
• The version or destination is displayed.
Procedure:
1. Press  ?/1  button to turn the set ON.
2. To enter the test mode, press the three buttons  x ,  GAME EQ
and  MOVIE EQ  simultaneously.
3. The destination is displayed.
4. Press  STOP  and  GROOVE  buttons simultaneously.
5. The version is displayed.
6. To exit from this mode, press  ?/1  button to turn the set OFF.
[CD Service Mode]
• This mode can run the CD sled motor freely. Use this mode, for
instance, when cleaning the pickup.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select the function “CD”.
3. To enter the test mode, press three buttons x ,  GAME EQ ,
and  OPEN/CLOSE  simultaneously.
4. The CD service mode is selected.
5. With the CD in stop status, press  
 button  to move the pickup
to outside track, or press  
 button to inside track.
6. To exit from this mode, perform as follows:
1) Move the pickup to the most inside track.
2) Press  ?/1  button to turn the set OFF.
Note:
 • Always move the pickup to most inside track when exiting from
this mode.  Otherwise, a disc will not be unloaded.
• Do not run the sled motor excessively, otherwise the gear can be
chipped.
+
17
HCD-GX40
SECTION 4
ELECTRICAL ADJUSTMENTS
FM Tuned Level Adjustment
Procedure:
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.
Adjustment Location: MAIN board
Null Adjustment
Procedure:
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.
Adjustment Location: MAIN board
FM RF Signal generator
75 
 coaxial
Carrier frequency : 98 MHz
Modulation           : AUDIO 1 kHz, 75 kHz
                              deviation (100%)
Output level          : 30 dB  (at 75 
 open)
FM ANTENNA terminal
(JK103)
set
FM RF Signal generator
75 
 coaxial
Carrier frequency : 98 MHz
Modulation           : AUDIO 1 kHz, 75 kHz
                              deviation (100%)
Output level          : 60 dB  (at 75 
 open)
FM ANTENNA terminal
(JK103)
set
T101: NULL
IFT101: AM IF
RV101: 
FM TUNED LEVEL
TUNER SECTION
AM RF Signal generator
30% amplitude
modulation by
400Hz signal
output level : as low as possible
AM ANTENNA terminal
(JK103)
set
AM IF Adjustment
Procedure:
1.
Set the frequency of the AM RF signal generator to 1000 kHz
(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).
3.
Adjust IFT101 so that the reading on level meter becomes in
maximum.
headphones jack (JK691)
level meter
set
16 
[MAIN BOARD]   Component side
18
HCD-GX40
CN731
TP731:
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
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
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
 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.
19
19
HCD-GX40
SECTION 5
DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in 
µ
F unless otherwise noted.  pF: 
µµ
F
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in 
 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 
0
 or dotted
line with mark 
0
 are criti-
cal for safety.
Replace only with part
number specified.
Note:
Les composants identifiés par
une marque 
0
 sont critiques
pour la sécurité.
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
).
Voltage variations may be noted due to normal produc-
tion tolerances.
no mark : FM
<
 
 
> :  CD
[
] : TAPE
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
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.)
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)
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
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
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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