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2012B33-1

© 

2012.02

•  HCD-GT220 is the amplifer, USB, CD player, tape 

deck and tuner section in MHC-GT220.

•  HCD-GT440 is the amplifer, USB, CD player, tape 

deck and tuner section in MHC-GT440.

•  HCD-GT660 is the amplifer, USB, CD player, tape 

deck and tuner section in MHC-GT660.

Photo: HCD-GT660

CD 
Section

Model Name Using Similar Mechanism

HCD-GT22

CD Mechanism Type

CDM74KF-K6BD91UR-WOD

Base Unit Name

BU-K6BD91UR-WOD74

Optical Pick-up Block Name

KSM-213DCP

TAPE
Section

Model Name Using Similar Mechanism

HCD-GT22

Tape Transport Mechanism Type

CWN42FF609

• “WALKMAN” and “WALKMAN” 

logo are registered trademarks of Sony 
Corporation.

• MICROVAULT is a trademark of Sony 

Corporation.

• MPEG Layer-3 audio coding 

technology and patents licensed from 

240V 50/60Hz
Front speaker

Power output (rated): 110 W + 110 W 
(at 6 Ω, 1 kHz, 1% THD)
RMS output power (reference): 
200 W + 200 W (per channel at 6 Ω, 
1 kHz, 10% THD)

Subwoofer

RMS output power (reference): 200 W 
(at 6 Ω, 80 Hz, 10% THD)

240V 50/60Hz
Front speaker

Power output (rated): 90 W + 90 W 
(at 6 Ω, 1 kHz, 1% THD)
RMS output power (reference): 
160 W + 160 W (per channel at 6 Ω, 
1 kHz, 10% THD)

Subwoofer

RMS output power (reference): 155 W 
(at 6 Ω, 80 Hz, 10% THD)

240V 50/60Hz

Power output (rated): 110 W + 110 W 
(at 6 Ω, 1 kHz, 1% THD)
RMS output power (reference): 
205 W + 205 W (per channel at 6 Ω, 
1 kHz, 10% THD)

AUDIO (phono jack): voltage 250 mV, 
impedance 47 kilohms
MIC (phone jack): sensitivity 1 mV, 
impedance 10 kilohms

 (USB) port: Type A

PHONES (stereo mini jack): accepts 
headphones of 8 Ω or more
SPEAKER: accepts impedance of 6 to 16 Ω
SUB WOOFER OUT (MHC-GT660/GT440 
only): accepts impedance of 6 to 16 Ω

Supported bit rate

MP3 (MPEG 1 Audio Layer-3): 
32

   320 kbps, VBR

Sampling frequencies

MP3 (MPEG 1 Audio Layer-3): 
32/44.1/48 kHz

Transfer speed

Full-Speed

Supported USB device

Mass Storage Class

Maximum current

500 mA

System: Compact disc and digital audio 
system
Laser Diode Properties

Emission Duration: Continuous
Laser Output*: Less than 44.6μW

*

at a distance of 200mm from the 
objective lens surface on the Optical 
Pick-up Block with 7mm aperture.

Frequency response: 20 Hz

   20 kHz

Signal-to-noise ratio: More than 90 dB
Dynamic range: More than 88 dB

Recording system: 4-track 2-channel, stereo
Frequency response: 50

   13,000 Hz (±3 

dB), using Sony TYPE I cassettes

FM stereo, FM/AM superheterodyne tuner

FM tuner section:

Tuning range:

87.5

   108.0 MHz (50 kHz step)

Antenna: FM lead antenna
Antenna terminals: 75 ohms unbalanced
Intermediate frequency: 10.7 MHz

AM tuner section:

Tuning range

530

   1,610 kHz (with 10 kHz tuning 

interval)
531

   1,602 kHz (with 9 kHz tuning 

interval)

Antenna: AM loop antenna, external 
antenna terminal
Intermediate frequency: 450 kHz

Power requirements

AC 120, 220 or 230

   240 V, 

50/60 Hz, Adjustable with voltage 
selector

Power consumption

HCD-GT660: 225 W
HCD-GT440: 250 W
HCD-GT220: 150 W

Dimensions (w/h/d) (excl. speakers)

HCD-GT660:
Approx. 280 × 365 ×425 mm
HCD-GT440/GT220:
Approx. 280 × 325 ×425 mm

Mass (excl. speakers)

HCD-GT660: 10.5 kg
HCD-GT440/GT220: 10.0 kg

change without notice.

NOTES  ON  CHIP  COMPONENT  REPLACEMENT
• 

Never reuse a disconnected chip component.

• 

Notice that the minus side of a tantalum capacitor may be dam-
aged 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.

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 

CAUTION
Use of controls or adjustments or performance of procedures 
other than those specifi ed herein may result in hazardous radia-
tion exposure.

This appliance is classifi ed as 
a CLASS 1 LASER product.
This marking is located on the 
rear exterior.

  .............................................   4

  ..................................................................   6

3-1.   Disassembly Flow ...........................................................   7
3-2.   Case (Side-L), Case (Side-R) ..........................................   8
3-3.   Case (Top) .......................................................................   8
3-4.   LID (CD) .........................................................................   9
3-5.   CD Mechanism Deck, USB R Board ..............................   9
3-6.   Front Panel Block ...........................................................   10
3-7.   Mecha Deck (CWM42FF609) ........................................   10
3-8.   Back Panel Block ............................................................   11
3-9.   MAIN Board, POWER Board ........................................   11
3-10.  CD Board ........................................................................   12
3-11.  DRIVER Board, SW Board ............................................   12
3-12.  Optical Pick-up Block (KSM-213D) ..............................   13
3-13.  SENSOR Board ..............................................................   13
3-14.  MOTOR (TB) Board.......................................................   14
3-15.  MOTOR (LD) Board ......................................................   14

MODE 

 .............................................................   15

ADJUSTMENTS 

 ......................   19

ADJUSTMENTS 

 ........................   20

7-1.  Block Diagram - CD SERVO, USB Section - ................   23
7-2.  Block Diagram - MAIN Section - ...................................   24
7-3.  Block Diagram - AMP Section - .....................................   25
7-4. Block 

Diagram 

 

- PANEL, POWER SUPPLY Section - ...........................   26

7-5.  Printed Wiring Board - CD Board - ................................   28
7-6.  Schematic Diagram - CD Board - ...................................   29
7-7.  Printed Wiring Boards - CHANGE Section - .................   30
7-8.  Schematic Diagram - CHANGE Section - .....................   31
7-9.  Printed Wiring Board - USB R Board - ..........................   32
7-10.  Schematic Diagram - USB R Board - .............................   33
7-11.  Printed Wiring Board - TC Board - .................................   34
7-12.  Schematic Diagram - TC Board - ...................................   35
7-13.  Printed Wiring Boards - MAIN Section - .......................   37
7-14.  Schematic Diagram - MAIN Section (1/4) - ...................   38
7-15.  Schematic Diagram - MAIN Section (2/4) - ...................   39
7-16.  Schematic Diagram - MAIN Section (3/4) - ...................   40
7-17.  Schematic Diagram - MAIN Section (4/4) - ...................   41
7-18.  Printed Wiring Board - MIC Board - ..............................   42
7-19.  Schematic Diagram - MIC Board - .................................   43
7-20. Printed Wiring Board 
 

- AMP Board (GT220/GT660) - .....................................   44

7-21.  Schematic Diagram - AMP Board (GT220/GT660) - .....   45
7-22.  Printed Wiring Board - AMP Board (GT440) - ..............   46
7-23.  Schematic Diagram - AMP Board (GT440) - .................   47
7-24. Printed Wiring Boards 
 

- SUB WOOFER Section (GT440/GT660) - ..................   48

7-25. Schematic Diagram 
 

- SUB WOOFER Section (GT440/GT660) - ..................   49

7-26.  Printed Wiring Boards - PANEL Section - .....................   50
7-27.  Schematic Diagram - PANEL Section - ..........................   51
7-28.  Printed Wiring Boards - KEY Section - ..........................   52
7-29.  Schematic Diagram - KEY Section - ..............................   53
7-30. Printed Wiring Board 
 

- TRANSFORMER Board (GT220/GT660) - ................   54

7-31. Schematic Diagram 
 

- TRANSFORMER Board (GT220/GT660) - ................   55

7-32. Printed Wiring Board 
 

- TRANSFORMER Board (GT440) -.............................   56

7-33. Schematic Diagram 
 

- TRANSFORMER Board (GT440) -.............................   57

8-1.   Case Section ....................................................................   66
8-2.   KEY TOP Board Section ................................................   67
8-3.   TC Mecha Deck Section .................................................   68
8-4.   PANEL Board Section ....................................................   69
8-5.   Front Panel Section .........................................................   70
8-6.   MAIN Board Section ......................................................   71
8-7.   POWER Board, SUB WOOFER Board Section ............   72
8-8.   Chassis Section ...............................................................   73
8-9.   CD Mechanism Deck, Section-1 
 (CDM74KF-K6BD91UR-WOD) 

...................................  

74

8-10.  CD Mechanism Deck, Section-2 
 (CDM74KF-K6BD91UR-WOD) 

...................................  

75

  ..............................   76

Accessories are given in the last of the electrical parts list.

The laser diode in the optical pick-up block may suffer electrostat-
ic 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 fl exible 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 refl ective surface by the objective lens in the optical 
pickup block. Therefore, when checking the laser diode emission, 
observe from more than 30 cm away from the objective lens.

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)

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 fl ow) 
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.

RELEASING  THE  ANTITHEFT  LOCK
The disc table lock function for the antitheft of an demonstration 
disc in the store is equipped.

Releasing Procedure:
1.  Press the [

?/1

] button to turn the power on.

2.  Press the [CD] button to select “CD”.
3.  While pressing the [

x

] button, press the [

Z

] button until “UN-

LOCKED” displayed on the fl uorescent indicator tube (around 
5 seconds).

Note: When 

“

LOCKED

”

 is displayed, the antitheft lock is not released 

by turning power on/off with the

 [

?/1

]

 button.

Note:  Work after removing the side panel refering to SECTION 3 DIS-

ASSEMBLY (page 7).