HCD-GX450, MHC-GX450 - Sony Audio Service Manual (repair manual)

hcd-gx450, mhc-gx450 service manual
Model
HCD-GX450 MHC-GX450
Pages
68
Size
7.54 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
hcd-gx450-mhc-gx450.pdf
Date

Read Sony HCD-GX450 / MHC-GX450 Service Manual online

SERVICE MANUAL
Sony Corporation
Home Audio Division
Published by Sony Techno Create Corporation
HCD-GX450
US Model
Canadian Model
MINI HI-FI COMPONENT SYSTEM
9-877-534-04
2006J16-1
© 2006.10
• HCD-GX450 is the tuner, deck, CD and
amplifier section in MHC-GX450.
SPECIFICATIONS
Ver. 1.3  2006.10
Amplifier section
AUDIO POWER SPECIFICATIONS
POWER OUTPUT AND TOTAL HARMONIC 
DISTORTION:
With 6 ohm loads, both channels driven, from 
120 – 10,000 Hz: rated 125 watts per channel 
minimum RMS power, with no more than 10% 
total harmonic distortion from 250 milliwatts to 
rated output.
Front speaker
Continuous RMS power output (reference):
125 + 125 watts (6 ohms at 
1 kHz, 10% THD)
Total harmonic distortion less than 0.07% (6 ohms at 
1 kHz, 60 W)
Sub woofer
Continuous RMS power output (reference):
150 watts (6 ohms at 
50 Hz, 10% THD)
Total harmonic distortion less than 0.07% (6 ohms at 
50 Hz, 75 W)
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 
cassettes
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range
87.5 – 108.0 MHz 
(100-kHz step)
Antenna
FM lead antenna
Antenna terminals
75 ohms unbalanced
Intermediate frequency
10.7 MHz
AM tuner section
Tuning range
530 – 1,710 kHz 
(with the tuning interval 
set at 10 kHz)
531 – 1,710 kHz 
(with the tuning interval 
set at 9 kHz)
Antenna
AM loop antenna
Antenna terminals
External antenna terminal
Intermediate frequency
450 kHz 
General
Power requirements
120 V AC, 60 Hz
Power consumption
USA models:
265 watts
Canadian models:
330 VA
Dimensions (w/h/d) incl. projecting parts and controls 
Amplifier/Tuner/Tape/CD section:
Approx. 280 
× 327 × 
425 mm
Mass 
Approx. 10.0 kg
Design and specifications are subject to change 
without notice.
Former Type Models
New Type Models
Model Name Using Similar Mechanism
New
New
CD
CD Mechanism Type
CDM74-F1BD81
CDM74KF-K6BD81C
Section
Optical Pick-up Name
KSM-215DCP/C2NP
KSM-213DCP/C2NP
Tape deck
Model Name Using Similar Mechanism
New
New
Section
Tape Transport Mechanism Type
CWM43FF-05
CWM43FF-05
2
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 
0
 OR DOTTED LINE WITH
MARK 
0
 ON 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.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 
0
 SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.
       After correcting the original service problem, perform the
following safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.
LEAKAGE
    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 a
VOM or battery-operated AC 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)
SAFETY  CHECK-OUT
HCD-GX450
The release method of a CD disc tray LOCK function
There is a disc lock function for the disc theft prevention for a
demonstration at a shop front in this machine.
Procedue:
1. Press the  ?/1  button to turn the set on.
2. Press two buttons of  x  and  Z (EJECT)  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  Z (EJECT)  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.
To Exposed Metal 
Parts on Set
0.15 
µ
F
1.5 k
AC
Voltmeter
(0.75 V)
Earth Ground
Fig. A.  Using an AC voltmeter to check AC leakage.
Unleaded solder
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size.)
 : LEAD FREE MARK
Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40°C higher than
ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350°C.
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!
• Strong viscosity
Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur such
as on IC pins, etc.
• Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
3
HCD-GX450
This appliance is classified as a CLASS 1 LASER product. The
CLASS 1 LASER PRODUCT MARKING is located on the rear
exterior.
Laser component in this product is capable
of emitting radiation exceeding the limit for
Class 1.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.
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.
NOTES  ON  HANDLING  THE  OPTICAL  PICK-UP
BLOCK  OR  BASE  UNIT
The laser diode in the optical pick-up block may suffer electrostatic
break-down 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.
TABLE OF CONTENTS
1. SERVICING NOTE
·························································· 4
2. GENERAL
·········································································· 6
3. DISASSEMBLY
3-1. Cover (Top) ····································································· 9
3-2. CD Door ·········································································· 9
3-3. Front Panel Section ······················································· 10
3-4. CD Mechanism Deck (CDM74-F1BD81) ···················· 10
3-5. Tape Mechanism Deck, Game Jack Board ··················· 11
3-6. PANEL Board ······························································· 11
3-7. Back Panel Section, SUB-TRANS Board ···················· 12
3-8. Power  Transformer ······················································· 12
3-9. MAIN Board ································································· 13
3-10. SUB-WOOFER Board ················································ 13
3-11. AMP Board ································································· 14
3-12. BD81A Board ····························································· 14
3-13. CONNECT Board ······················································· 15
3-14. DRIVER Board, SW Board ········································ 15
3-15. Optical Pick-up (KSM-215DCP/C2NP) ····················· 16
3-16. SENSOR Board ·························································· 16
3-17. MOTOR (TB) Board ··················································· 17
3-18. MOTOR (LD) Board ·················································· 17
4. TEST MODE
···································································· 18
5. DIAGRAMS
5-1. Block Diagrams – PANEL Section – ···························· 22
– MAIN Section – ······················································· 23
– BD/DRIVER Section – ············································ 24
– SUB-WOOFER Section – ········································ 25
5-2. Printed Wiring Board  – BD81A Section – ··················· 26
5-3. Schematic Diagram  – BD81A Section – ····················· 27
5-4. Printed Wiring Board
– CD MECHANISM Section – ··································· 28
5-5. Schematic Diagram  – CD MECHANISM Section – ··· 29
5-6. Printed Wiring Board  – MAIN Section – ···················· 30
5-7. Schematic Diagram  – MAIN Section (1/2) – ·············· 31
5-8. Schematic Diagram  – MAIN Section (2/2) – ·············· 32
5-9. Printed Wiring Board  – PANEL COMB Section – ······ 33
5-10. Schematic Diagram  – PANEL COMB Section – ······ 34
5-11. Printed Wiring Board  – SUB-WOOFER Section – ··· 35
5-12. Schematic Diagram
– SUB-WOOFER Section – ········································ 36
5-13. Printed Wiring Board  – PANEL Section – ················· 37
5-14. Schematic Diagram  – PANEL Section (1/2) – ·········· 38
5-15. Schematic Diagram  – PANEL Section (2/2) – ·········· 39
5-16. Printed Wiring Board  – TRANS Section – ················ 40
5-17. Printed Wiring Board  – AMP Section – ····················· 41
5-18. Schematic Diagram  – AMP POWER Section – ········ 42
5-19. IC Pin Function Description ······································· 46
6. EXPLODED VIEWS
6-1. MAIN Section ······························································· 51
6-2. Front Panel Section ······················································· 52
6-3. MAIN Board Section ···················································· 53
6-4. CD Mechanism Deck Section -1 (CDM74-F1BD81) ··· 54
6-5. CD Mechanism Deck Section -2 (CDM74-F1BD81) ··· 55
7. ELECTRICAL PARTS LIST
······································· 56
4
HCD-GX450
SECTION 1
SERVICING NOTE
 SERVICE POSITION -1 (AMP BOARD)
front panel
CD mechanism deck
AMP board
To inspect the AMP board, turn both of the front panel 
and the CD mechanism deck so that the left side of the product faces down.
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