Sony HCD-GX25 - System Components User manual

1
Ver 1.0 2003. 03
Model Name Using Similar Mechanism NEW
CD CD Mechanism Type CDM74F-K6BD72
Section Optical Pick-up Name KSM-213DCP
Tape deck Model Name Using Similar Machanism NEW
Section Tape Transport Mechanism Type CWM43FF-05
SERVICE MANUAL
US Model
HCD-GX25
Amplifier section
Continuous RMS power output (reference)
120+120 watts (6 ohms at
1 kHz, 10% THD)
Total harmonic distortionless than 0.07%
(6 ohms at 1 kHz, 60W)
Inputs
GAME INPUT AUDIO L/R (phono jacks):
voltage 250 mV,
impedance 47 kilohms
GAME INPUT VIDEO (phono jack):
1 Vp-p, 75 ohms
Outputs
PHONES (stereo mini jack):
accepts headphones of
8 ohms or more
VIDEO OUT (phono jack):
max. output level 1Vp-p,
unbalanced, Sync negative,
load impedance 75 ohms
SPEAKER: accepts impedance of 6 to
16 ohms
SPECIFICATIONS
CD player section
System Compact disc and digital
audio system
Laser Semiconductor laser
(λ=780 nm)
Emission duration:
continuous
Frequency response 2 Hz – 20 kHz (±0.5 dB)
Wavelength 780 – 790 nm
Signal-to-noise ratio More than 90 dB
Dynamic range More than 90 dB
Tape deck section
Recording system 4-track 2-channel stereo
Frequency response 50 – 13,000 Hz (±3 dB),
using Sony TYPE I
cassette
Sony Corporation
Home Audio Company
Published by Sony Engineering Corporation
9-877-125-01
2003C0400-1
© 2003. 03
– Continued on next page –
MINI HIFI COMPONENT SYSTEM
•HCD-GX25isthetuner, deck, CD
and amplifier section in MHC-
GX25.

2
HCD-GX25
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED LINE
WITH MARK 0ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 – 108.0 MHz
Antenna FM lead antenna
Antenna terminals 75 ohm unbalanced
Intermediate frequency 10.7 MHz
AM tuner section
Tuning range 530 – 1,710 kHz (with the tuning
interval set at 10 kHz)
Antenna AM loop antenna
Antenna terminals External antenna terminal
Intermediate frequency 450 kHz
General
Power requirements 120 V AC, 60 Hz
Power consumption 120 watts
Dimensions (w/h/d) Approx. 280 ×325 ×407 mm
Mass Approx. 8.5 kg
Supplied accessories: AM loop antenna (1)
Remote Commander (1)
Batteries (2)
FM lead antenna (1)
Speaker pads (8)
Design and specifications are subject to change without
notice.
To Exposed Metal
Parts on Set
0.15µF 1.5k
Ω
AC
voltmeter
(0.75V)
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs,screws,
and all other exposed metal parts forAC leakage. Check leakage as
described below.
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of aVOM
or battery-operatedAC voltmeter. The “limit” indication is 0.75
V, so analog meters must have an accurate low-voltage scale. The
Simpson 250 and Sanwa SH-63Trd are examples of a passive
VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig.A)

3
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous
radiation exposure.
HCD-GX25
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
breakdown because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.
Laser component in this product is capable
of emitting radiation exceeding the limit for
Class 1.
Notes on Chip Component Replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be
damaged by heat.
Flexible Circuit Board Repairing
•Keep the temperature of soldering iron around 270°C during
repairing.
•Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
•Be careful not to apply force on the conductor when soldering
or unsoldering.
MODEL IDENTIFICATION
– BACK PANEL –
PARTS No.
MODEL PARTS No.
US models 4-244-697-01

4
TABLE OF CONTENTS
1. GENERAL
Main Unit ................................................................................ 5
Remote Control ....................................................................... 6
2. DISASSEMBLY
2-1. Case (Top) ........................................................................... 8
2-2. CD Door .............................................................................. 8
2-3. Front Panel Section ............................................................. 9
2-4. CD Mechanism Block .......................................................10
2-5. Tape Mechanism Deck ...................................................... 10
2-6. Panel Board, 1 Stream Led Board, Remote Board............ 11
2-7. Game Jack Board, H/P Jack Board ................................... 11
2-8. Back Panel Section............................................................ 12
2-9. Main Board ....................................................................... 12
2-10. Amp Board ........................................................................ 13
2-11. Driver Board, Sw Board.................................................... 13
2-12. CD Block Assy .................................................................. 14
2-13. Sensor Board ..................................................................... 14
2-14. Motor (TB) Board ............................................................. 15
2-15. Motor (LD) Board .............................................................15
2-16. Optical Pick-up ................................................................. 16
3. DIAGRAMS
3-1. IC Pin Description............................................................. 17
3-2. Circuit Boards Location .................................................... 19
3-3. Printed Wiring Boards –CD Mechanism Section (1/2)– ... 21
3-4. Printed Wiring Boards –CD Mechanism Section (2/2)– ... 22
3-5. Schematic Diagram –CD Mechanism Section– ................ 23
3-6. Printed Wiring Boards –Main Section– ............................ 24
3-7. Schematic Diagram –Main Section (1/3)– ........................ 25
3-8. Schematic Diagrams –Main Section (2/3)– ...................... 26
3-9. Schematic Diagram –Main Section (3/3)– ........................ 27
3-10. Printed Wiring Boards –Panel Section– ............................28
3-11. Schematic Diagram –Panel Section– ................................ 29
3-12. Printed Wiring Board –Power Amp Section– ................... 30
3-13. Schematic Diagram –Power Amp Section (1/2)– ............. 31
3-14. Schematic Diagram –Power Amp Section (2/2)– ............. 32
3-15. Printed Wiring Board –Transformer Section– .................. 33
3-16. Schematic Diagram –Transformer Section– ..................... 34
3-17. IC Block Diagrams............................................................ 35
4. EXPLODED VIEWS
4-1. Main Section ..................................................................... 37
4-2. Front Panel Section ........................................................... 38
4-3. Main Board Section .......................................................... 39
4-4. CD Mechanism Deck Section (1) ..................................... 40
4-5. CD Mechanism Deck Section (2) ..................................... 41
4-6. Optical Pick-up Section..................................................... 42
5. ELECTRICAL PARTS LIST ........................................ 43
HCD-GX25

5
HCD-GX25
SECTION 1
GENERAL This section is extracted
from instruction manual.

6
HCD-GX25

7
HCD-GX25
SECTION 2
DISASSEMBLY
Note : Disassemble the unit in the order as shown below.
2-1. CASE (TOP)
(Page 8)
2-2. CD DOOR
(Page 8)
SET
2-3. FRONT PANEL SECTION
(Page 9)
2-7. GAME JACK BOARD,
H/P JACK BOARD
(Page 11)
2-12. CD BLOCK ASSY
(Page 14)
2-16. OPTICAL PICK-UP
(Page 16)
2-11. DRIVER BOARD,
SW BOARD
(Page 13)
2-14. MOTOR (TB) BOARD
(Page 15)
2-4. CD MECHANISM BLOCK
(Page 10) 2-5. TAPE MECHANISM DECK (Page 10)
2-6. PANEL BOARD,
1 STREAM LED BOARD,
REMOTE BOARD
(Page 11)
2-15. MOTOR (LD) BOARD
(Page 15)
2-13. SENSOR BOARD
(Page 14)
2-8. BACK PANEL SECTION
(Page 12)
2-9. MAIN BOARD
(Page 12)
2-10. AMP BOARD
(Page 13)

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HCD-GX25
2-2. CD DOOR
Note : Follow the disassembly procedure in the numerical order given.
2-1. CASE (TOP)
case (side-R)
case (side-L)
5
qd
qs
qs
q;
6
two screws (case 3 TP2)
qf case (top)
8 screw
(+BVTP 3
× 10)
3 screw
(+BVTP 3
× 10
)
9 screw
(+BVTT 3
× 8)
4 screw
(+BVTT 3
× 8)
1 two screws
(case 3 TP2)
qa two screws (+BVTP 3 × 10)
7 screw (case 3 TP2)
2 screw (case 3 TP2)
2 Pull-out the disc tray.
4 CD door
1 Turn the pulley to the direction of arrow.
pulley
Front panel side
CD mechanism deck (CDM74F-K6BD72)
3

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HCD-GX25
2-3. FRONT PANEL SECTION
1 CN605
2 CN304
(flat type)
4 CN310
5 CN202
6 CN203
7 CN305
3 CN311
(flat type)
trans board
qa three screws (+BVTP 3 × 6 )
qs front panel section
0 screw
(+BVTP 3
× 10)
8 screw
(+BVTP 3
× 10)
9 screw
(+BVTP 3
× 10)

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HCD-GX25
2-5. TAPE MECHANISM DECK
2-4. CD MECHANISM BLOCK
1 CN701
MAIN boardMAIN board
2 CN312
(flat type
)
3 three screws
(+BVTP 3
× 10
)
4 CD mechanism block
2 six screws
(+BVTP 2.6
× 8
)
3 tape mechanism deck
1 connector

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HCD-GX25
2-6. PANEL BOARD, 1 STREAM LED BOARD, REMOTE BOARD
2-7. GAME JACK BOARD, H/P JACK BOARD
1 volume knob
6 PANEL board
8 1 STREAM LED board
0 REMOTE board
9 CN607
2 three screws
(+BVTP 2.6
× 8)
3 two screws
(+BVTP 2.6
× 8
)
4 two screws
(+BVTP 2.6
× 8)
7 two screws
(+BVTP 2.6
× 8)
5 four screws
(+BVTP 2.6
× 8)
1 two screws
(+BVTP 2.6
× 8)
2 GAME JACK boar
d
4 H/P JACK board
3 screw
(+BVTP 2.6
× 8)

12
HCD-GX25
2-8. BACK PANEL SECTION
2-9. MAIN BOARD
4 back panel section
chassis section
3 two screws
(+BVTT 3
× 6)
2 two screws
(+BVTP 3
× 10)
1 CN101
(flat type)
2 MAIN boar
d
1 two screws
(+BVTT 3
× 6)
MAIN board

13
HCD-GX25
2-10. AMP BOARD
2-11. DRIVER BOARD, SW BOARD
6 AMP board
1 CN902
2 screw
(+BVTP 3
× 10
)
two claws
4 screw
(+BVTP 3
× 10)
5 screw
(+BVTP 3
× 10)
3 screw
(+BVTP 3
× 10)
6 DRIVER boar
d
4 SW board
1 CN704
2 CN703
7 CN702 (flat type)
5 two screws
(+BTTP (M2.6))
3 screw
(+BTTP (M2.6))

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HCD-GX25
2-12. CD BLOCK ASSY
2-13. SENSOR BOARD
qa
5
two coil springs
(insulator)
9 two coil springs
(insulator)
6 two insulators
0 two insulators
qs screw (+BTP 2.6x 8)
7 two screws
(BVTT M2.6)
2 holder (213) assy
8 two stoppers (BU)
qd Remove the four solderings of motor.
qf CN708 (flat type)
qg BD board
qh CD block assy
3 floating screw
(+PTPWH M2.6)
1 floating screw
(+PTPWH M2.6)
4 two floating screws
(+PTPWH M2.6)
2 tray
3 belt (table)
5 pulley (table)
8 screw
(+BTTP (M2.6))
9 SENSOR board
7 gear (geneva)
0 CN731
1 floating screw
(+PTPWH M2.6)
6 floating screw
(+PTPWH M2.6)
4 floating screw
(+PTPWH M2.6)

15
HCD-GX25
2-14. MOTOR (TB) BOARD
2-15. MOTOR (LD) BOARD
4 Remove the two solderings of motor.
3 MOTOR (TB) board
5 table motor assy (M741)
2 two screws
(+BTTP (M2.6))
1
4 Remove the two solderings of motor.
3 MOTOR (LD) board
1 belt (loading)
5 loading motor assy (M751)
2 two screws
(+BTTP (M2.6))

16
HCD-GX25
2-16. OPTICAL PICK-UP
1 gear (A
)
claw
3 sled shaft
5 optical pick-up
2
4

17
HCD-GX25
SECTION 3
DIAGRAMS
3-1. IC PIN DESCRIPTION
• IC601 LC876756C-51H7-E (SYSTEM CONTROL, FLD CONTROL) (PANEL BOARD)
Pin No. Pin Name I/O Pin Description
1SYS MUTE O System mute signal output
2BU1924 DATA I Not used in this set. (Connected to ground.)
3PWR DOWN I Power down signal input
4LC78646 RESET O CD reset signal output to the IC721 (LC78646)
5LC78646 CE O CD CE signal output to the IC721 (LC78646)
6LC78646 CE (MP3) O CD CE (MP3) signal output (Not used in this set.)
7M61519 CLK O Clock signal output to the IC301 (M61529FP)
8BU2099FV LCK O LCK signal output to the IC309 (BU2099FV)
9 LC72121 CE O CE signal output to the TU701 (tuner pack)
10 LC78684 SYNC I SYNC signal input
11 RESET I Reset signal input from the IC603
12 XT1 I Oscillater connect pin (32.768 kHz)
13 XT2 O Oscillater connect pin (32.768 kHz)
14 VSS1 — Ground pin
15 CF1 I Ceramic vibrator connect pin (8.64 MHz)
16 CF2 O Ceramic vibrator connect pin (8.64 MHz)
17 VDD — Power supply pin (+3.3 V)
18 TAPE A STAT I Tape A start signal input
19 TAPE B STAT I Tape B start signal input
20 CD ENCODER I CD encoder switch signal input
21 SW ON/OFF SENSOR I Switch control on/off signal input
22 STREAM IN I Stream in signal input
23 VACS I VACS signal input
24 KEY2 I Key signal input 2
25 KEY1 I Key signal input 1
26 KEY0 I Key signal input 0
27 PROTECTOR (HOLD) I Protector (Hold) signal input
28 REMOCON IN I Remote control signal input from the RM601
29 BU1924 CLK I Not used in this set. (Connected to ground.)
30 – 41 G12 – G1 O FLD control signal output
42 – 45 P1 – P4 O FLD control signal output
46 VDD3 — Power supply pin (+3.3 V)
47 – 50 P5 – P8 O FLD control signal output
51 VPP — Ground pin
52 – 55 P9 – P12 O FLD control signal output
56 SW1 (a) P13 O FLD control signal output
57 SW2 (b) P14 O FLD control signal output
58 SW3 (c) P15 O FLD control signal output
59 SW4 (d) P16 O FLD control signal output
60 SW5 P17 O FLD control signal output
61 SW6 P18 O FLD control signal output
62 SW7 P19 O FLD control signal output
63 SW8 P20 O FLD control signal output
64, 65 P21, P22 O FLD control signal output
66 ENTER LED O Not used in this set. (Open)
67 MD/VIDEO LED O Not used in this set. (Open)
68 GAME LED O GAME LED (LED612) drive signal output
69 TAPE LED O TAPE LED (LED609) drive signal output
70 TUNER LED O TUNER LED (LED608) drive signal output
71 CD LED O CD LED (LED607) drive signal output
72 VDD4 — Power supply pin (+3.3 V)

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HCD-GX25
Pin No. Pin Name I/O Pin Description
73 CD VDD — CD power supply pin
74 TUNER TUNED I Tuner tuning signal input from the TU701 (tuner pack)
75 TUNER STEREO I Tuner stereo signal input from the TU701 (tuner pack)
76 CD DRF I CD DRF signal input from the IC721 (LC78646)
77 CD WRQ I CD WRQ signal input from the IC721 (LC78646)
78 CD NUMBER SENSOR I CD number sensor signal input
79 TAPE AMS IN I Tape AMS signal input
80 VR ENCODER A I VR encoder (VR601) signal input
81 VR ENCODER B I VR encoder (VR601) signal input
82 TAPE REEL A I Tape reel A signal input
83 TAPE REEL B I Tape reel B signal input
84 MODE SW IN I Mode switch signal input
85 STREAM 1 LED O Stream LED (LED611) drive signal output
86 CD MUTE O CD mute signal output
87 STREAM 3 LED O Not used in this set. (Open)
88 MECHA VCC O Mechanism power control signal output “L”: ON, “H”: OFF
89 VSS2 — Ground pin
90 VDD2 — Power supply pin (+3.3 V)
91 TAPE SOL A O Tape SOL A control signal output “L”: ON, “H”: OFF
92 TAPE SOL B O Tape SOL B control signal output “L”: ON, “H”: OFF
93 POWER LED O POWER LED (LED614) drive signal output
94 POWER RELAY O Power relay signal output
95 LC72121/M61529 OSerial data signal output
/BU2099FV DO
96 LC72121 DI I Serial data signal input
97 LC72121/BU2099FV CLK O Serial clock signal output
98 LC78646/LC78684 DO O Serial data signal output
99 LC78646/LC78684 DI I Serial data signal input
100 LC78646/LC78684 CLK O Serial clock signal output

19
HCD-GX25
3-2. CIRCUIT BOARDS LOCATION
MAIN board
DRIVER board
SW board
MOTOR (LD) board MOTOR (TB) boar
d
VIDEO OUT board
BD board
SENSOR board
TRANS board
AMP board
H/P JACK board
GAME JACK board
PANEL board
REMOTE board
1 STREAM LED board

20
HCD-GX25
THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is
printed in each block.)
for schematic diagram:
•All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
•All resistors are in Ωand 1/4W or less unless otherwise
specified.
•%: indicates tolerance.
•f: internal component.
•C: panel designation.
•A: B+ Line.
•B: B– Line.
•H: adjustment for repair.
•Voltage and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
•Voltagesaretakenwith a VOM (Input impedance 10 MΩ).
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
f: AM
E: PB (DECK A)
d: PB (DECK B)
G: REC (DECK B)
J: CD
c: digital out
for printed wiring boards:
•X: parts extracted from the component side.
•Y: parts extracted from the conductor side.
•x: parts mounted on the conductor side.
•: Pattern from the side which enables seeing.
(The other layer’s patterns are not indicated.)
Note: The components identified by mark 0or dotted line
with mark 0are critical for safety.
Replace only with part number specified.
• Waveforms
— BD Board —
(MODE: CD PLAY)
1
2
0.9Vp-p
3
16.9344MHz
IC721 rl (XIN)
4
IC721 tk (LRSY)
1Vp-p
0.9Vp-p
3Vp-p
IC721 4(RF)
IC721 3(EFMIN)
22µsec
— PANEL Board —
1
2
8.64MHz
IC601 qg (CF1)
32.768kHz
IC601 qs (XT1)
1.2Vp-p
1Vp-p