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Model Name Using Similar Mechanism

NEW

DVD

DVD Mechanism Type

CDM74D-DVBU23

Section

Base Unit Name

DVBU23

Optical Pick-up Name

TDP022W

Tape

Model Name Using Similar Mechanism

HCD-GN800

Section

Tape Transport Mechanism Type

CWM43RR23

E Model

2005K02-1

C

 2005.11

HCD-GN77D is the amplifier, DVD
player, tape deck and tuner section in
MHC-GN77D.

– Continued on next page –

Amplifier section
The following are measured at AC 120, 127, 220, 240V 50/60 Hz
DIN power output (rated)
Front speaker:

110 + 110 watts (6 ohms at 1 kHz, DIN)

Center speaker:

30 watts (8 ohms at 1 kHz, DIN)

Surround speaker:

30 + 30 watts (8 ohms at 1 kHz, DIN)

Continuous RMS power output (reference)
Front speaker:

150 + 150 watts (6 ohms at 1 kHz, 10% THD)

Center speaker:

40 watts (8 ohms at 1 kHz, 10% THD)

Surround speaker:

40 + 40 watts (8 ohms at 1 kHz, 10% THD)

Inputs
GAME (VIDEO):

1 Vp-p, 75 ohms (phono jack)

GAME (AUDIO):

Voltage 250 mV,

(phono jacks)

impedance 47 kilohms

MD/VIDEO (AUDIO) IN: voltage 450 mV/250 mV,
(phono jacks)

impedance 47 kilohms

MIC:

sensitivity 1 mV,

(phone jack)

impedance 10 kilohms

Outputs
AUDIO OUT:

Voltage 250 mV

(phono jacks)

impedance 1 kilohms

VIDEO OUT:

max. output level 1 Vp-p,

(phono jack)

unbalanced, Sync.
negative load impedance 75 ohms

COMPONENT VIDEO
OUT: Y:

1 Vp-p, 75 ohms

PB/CB:

0.7 Vp-p, 75 ohms

PB/CR:

0.7 Vp-p, 75 ohms

S VIDEO OUT
(4-pin/mini-DIN jack):

Y: 1 Vp-p, unbalanced, Sync negative
C: 0.286 Vp-p load impedance 75 ohms

PHONES:

accepts headphones of 8 ohms or more

(stereo mini jack)
FRONT SPEAKER:

accepts impedance of 6 to 16 ohms

SUBWOOFER OUT:

Voltage 250 mV

(phono jack)

impedance 1 kilohms

SURROUND SPEAKER: accepts impedance of 8 ohms to 16 ohms
CENTER SPEAKER:

accept impedance of 8 ohms to 16 ohms

Disc player section
Laser

Semiconductor laser
(DVD: 

λ = 650 nm, CD: λ = 780 nm)

Emission duration: continuous

Frequency response

DVD (PCM 48 kHz): 2 Hz – 22 kHz = (

±1dB)

CD: 2 Hz – 20 kHz (

±0.5 dB)

Video color system format NTSC, PAL
(except Latin American models)
DVD DIGITAL OUT (OPTICAL)
(Square optical connector jack, rear panel)
Wave length

660 nm

2

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 the soldering iron around 270 ˚C dur-

ing 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.

CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.

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  PUB-
LISHED  BY  SONY.

This appliance is classified as
a CLASS 1 LASER product.
The CLASS 1 LASER
PRODUCT MARKING is
located on the rear exterior.

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 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.

Tape player section
Recording system

4-track 2-channel stereo

Frequency response

50 – 13,000 Hz (

±3 dB), using Sony TYPE I

cassette

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
North and Latin American models:

530 – 1,710 kHz
(with the interval set at 10 kHz)
531 – 1,710 kHz
(with the interval set at 9 kHz)

Saudi Arabian models:

531 – 1,602 kHz
(with the interval set at 9 kHz)

Other models:

531 – 1,602 kHz
(with the interval set at 9 kHz)
530 – 1,710 kHz
(with the interval set at 10 kHz)

Antenna

AM loop antenna

Antenna terminals

External antenna terminal

Intermediate frequency

450 kHz

General
Power requirements
Saudi Arabian Models:

120 - 127 V, 220 V or 230 - 240 V AC, 50/60 Hz
Adjustable with voltage selector

Thai models:

 220 V AC, 50/60 Hz

Other models:

120 V, 220 V or 230 - 240 V AC, 50/60 Hz
Adjustable with voltage selector

Power consumption

220 watts

Dimensions (w/h/d)

Approx. 280 x 360 x 386.5 mm

Mass :

Approx. 12.9 kg

Design and specifications are subject to change without notice.

3

................................................

4

Location of Controls .......................................................

5

3-1. Case .................................................................................

8

3-2. Loading (Panel) ...............................................................

8

3-3. Front Panel Assy .............................................................

9

3-4. Tuner Pack, Sub Trans Board .........................................

9

3-5. DVD Mechanism Deck ................................................... 10
3-6. Game In Board, Tape Mechanism Deck ......................... 10
3-7. CD Switch Board, Display Board .................................. 11
3-8. Volume Board .................................................................. 11
3-9. Back Panel, Subwoofer Board ........................................ 12
3-10. Main Board ...................................................................... 12
3-11. Power Amp Board ........................................................... 13
3-12. Video Board, DMB03 Board, Regulator Board ............. 13
3-13. SW Board, Driver Board ................................................ 14
3-14. RF Board, Pick-up Unit .................................................. 14
3-15. Sensor Board ................................................................... 15
3-16. Motor (TB) Board ........................................................... 15
3-17. Motor (LD) Board ........................................................... 16

.............................................................. 17

....................... 19

Deck section .................................................................... 19
Video Section .................................................................. 22

7-1. Circuit Board Location ................................................... 24
7-2. Block Diagram  – DVD DSP (1/2)  Section – ................ 26

Block Diagram  – DVD DSP (2/2)  Section – ................ 27
Block Diagram  – Tuner/Tape Deck Section – ............... 28
Block Diagram  – Main Section – .................................. 29
Block Diagram  – Amp Section – ................................... 30
Block Diagram  – Display Section – .............................. 31

7-3. Printed Wiring Board  – RF Board – .............................. 32
7-4. Schematic Diagram  – RF Board – ................................. 33
7-5. Printed Wiring Board  – DVD Mechanism Board – ...... 34
7-6. Schematic Diagram  – DVD Mechanism Board – ......... 35

7-7. Printed Wiring Board  – DMB03 Board (Side A)– ........ 36

Printed Wiring Board  – DMB03 Board (Side B)– ........ 37

7-8. Schematic Diagram  – DMB03 Board (1/8) – ................ 38
7-9. Schematic Diagram  – DMB03 Board (2/8) – ................ 39
7-10. Schematic Diagram  – DMB03 Board (3/8) – ................ 40
7-11. Schematic Diagram  – DMB03 Board (4/8) – ................ 41
7-12. Schematic Diagram  – DMB03 Board (5/8) – ................ 42
7-13. Schematic Diagram  – DMB03 Board (6/8) – ................ 43
7-14. Schematic Diagram  – DMB03 Board (7/8) – ................ 44
7-15. Schematic Diagram  – DMB03 Board (8/8) – ................ 45
7-16. Printed Wiring Board  – Video, Regulator Board – ....... 46
7-17. Schematic Diagram  – Video, Regulator Board – .......... 47
7-18. Printed Wiring Boards  – Main Board – ......................... 48
7-19. Schematic Diagram  – Main Board (1/4) – .................... 49
7-20. Schematic Diagram  – Main Board (2/4) – .................... 50
7-21. Schematic Diagram  – Main Board (3/4) – .................... 51
7-22. Schematic Diagram  – Main Board (4/4) – .................... 52
7-23. Printed Wiring Boards

– Game In, CD Switch Board – ...................................... 53

7-24. Schematic Diagram

– Game In, CD Switch Board – ...................................... 54

7-25. Printed Wiring Board  – Display Board – ...................... 55
7-26. Schematic Diagram  – Display Board – ......................... 56
7-27. Printed Wiring Board  – Power Amp Board – ................ 57
7-28. Schematic Diagram  – Power Amp Board – .................. 58
7-29. Printed Wiring Board  – Surround Board – .................... 59
7-30. Schematic Diagram  – Surround Board – ....................... 60
7-31. Printed Wiring Boards  – Trans Board – ........................ 61
7-32. Schematic Diagram  – Trans Board – ............................. 62
7-33. IC Block Diagram ........................................................... 63
7-34. IC Pin Function Description ........................................... 68

8-1. Case, Back Panel DMB03 Board Section ...................... 79
8-2. Front Panel Section ......................................................... 80
8-3. Chassis Section ............................................................... 81
8-4. DVD Mechanism Deck Section-1

(CDM74D-DVBU43) ..................................................... 82

8-5. DVD Mechanism Deck Section-2

(CDM74D-DVBU43) ..................................................... 83

.................................. 84

4

The laser diode in the optical pick-up block may suffer electro-
static 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 emis-
sion, observe from more than 30 cm away from the objective lens.

LASER  DIODE  AND  FOCUS  SEARCH  OPERATION
CHECK
Carry out the “S curve check” in “CD section adjustment” and
check that the S curve waveforms is output three times.

MODEL

PART No.

SP model

4-246-185-1[]

MY model

4-246-185-2[]

EA model

4-246-185-3[]

TH model

4-246-185-4[]

E3, E15 models

4-246-185-5[]

•

Abbreviation
E3

: 240 V AC Area in E model

EA

: Saudi Arabia model

E15

: Iran model

SP

: Singapore model

MY

: Malaysia model

TH

: Thai model

• This mode let you lock the disc trays. When this mode is acti-

vated, the disc tray will not open when 

Z

OPEN/CLOSE

 but-

ton or 

[DISC SKIP/EX-CHANGE]

 button is pressed. The mes-

sage “LOCKED” will be displayed in the will be displayed on
the fluorescent indicator tube.

1. Press 

?/1

 button to turn the set ON.

2. Select DVD function.

3. Press  

x

  button and 

Z

OPEN/CLOSE

 button simultaneously

and hold down until “LOCKED” or “UNLOCKED” displayed
on the fluorescent indicator tube (around 5 seconds).

NOTES ON DMB03 BOARD EXCHANGE
If a DMB03 board is exchanged, “DRIVE AUTO ADJUSTMENT”
may be unable to be performed. In this case, initialize a memory in
the following procedure.

1. Starting Test  Mode (see Supplement-1 page 2).
2. Press the 2 button of remote commander to set the Drive

Manual Operation (see Supplement-1 page 4).

3. Press the 6 button of remote commander to set the Memory

Check (see Supplement-1 page 6).

4. Press the [CLEAR] button of remote commander to initialize

a memory.