Sony MHCGRX-9900 Service manual

MHC-GRX9900

SERVICE MANUAL

Photo: HCD-RXD9 (US model)

Dolby noise reduction manufactured under license
from Dolby Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol a are trade­marks of Dolby Laboratories Licensing Corporation.

CD
Section

Tape deck
Section

ARGENTINE Model

Model Name Using Similar Mechanism NEW
CD Mechanism Type CDM38LH-5BD32L
Base Unit Name BU-5BD32L
Optical Pick-up Name KSS-213D/Q-NP
Model Name Using Similar Mechanism NEW
Tape Transport Mechanism Type TCM-230AWR2

Amplifier section

US model:

AEP and UK models:
DIN power output (rated) 120 + 120 watts

(8 ohms at 1 kHz, DIN)

Continuous RMS power output (reference)

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

Music power output (reference)

275 + 275 watts
(8 ohms at 1 kHz, 10% THD)

SPECIFICATIONS

E models:
The following measured at AC 120, 220, 240 V 50/60 Hz
DIN power output (rated) 200 + 200 watts

(6 ohms at 1 kHz, DIN)

Continuous RMS power output (reference)

250 + 250 watts
(6 ohms at 1 kHz, 10% THD)

– Continued on next page –

MICROFILM

MINI Hi-Fi COMPONENT SYSTEM

Specifications (continued)

Inputs
MD/VIDEO (AUDIO) IN: voltage 450 mV/250mV,
(phono jacks) impedance 47 kilohms
MIX MIC: (phone jack) sensitivity 1 mV, impedance 10

kilohms

Outputs
MD OUT: voltage 250 mV,
(phono jacks) impedance 1 kilohms
PHONES: accepts headphones of 8 ohms
(stereo phone jack) or more
SPEAKER:
E models: accepts impedance of 6 to 16 ohms

SUPER WOOFER :

Voltage 1 V, impedance 1 kilohm

CD player section

System Compact disc and digital audio system
Laser Semiconductor laser (λ=780nm)

Emission duration: continuous

Laser output Max. 44.6 µW*

*This output is the value measured at
distance of 200 mm from the objective
lens surface on the Optical Pick-up

Block with 7 mm aperture.
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
CD OPTICAL DIGITAL OUT
(Square optical connector jack, rear panel)
Wavelength 600 nm
Output Level -18 dBm

Tape player section

Recording system 4-track 2-channel stereo
Frequency response 40 - 13,000 Hz (±3 dB),
(DOLBY NR OFF) using Sony TYPE I cassette

40 - 14,000 Hz (±3 dB),

using Sony TYPE II 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

Antenna AM loop antenna
Antenna terminals External antenna terminal
Intermediate frequency 450 kHz

General

Power requirements
ARGENTINE model: 120 V, 220V AC, 50/60 Hz

Power consumption
ARGENTINE model: 240 watts

Dimensions (w/h/d) Approx. 280 × 360 × 395 mm

Mass
ARGENTINE model: Approx. 12.0 kg

Supplied accessories: AM loop antenna (1)

Design and specifications are subject to change without notice.

Ajustable with voltage selector

1

(13

/8 × 141/4 × 155/8 in.)

Remote Commander (1)
Batteries (2)
FM lead antenna (1)
Speaker cords (2)
Front speaker pads (8)

AM tuner section

Tuning range
2 Band type:
ARGENTINE model: 530 - 1,710 kHz

(with the interval set at 10 kHz)

531 - 1,710 kHz

(with the interval set at 9 kHz)

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK ! OR DOTTED
LINE WITH MARK ! 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.

– 2 –

TABLE OF CONTENTS

SECTION 1

SERVICING NOTES

1. SERVICING NOTES ............................................... 3

2. GENERAL

Location of Controls ....................................................... 6

Setting the Time .............................................................. 7

3. DISASSEMBLY ......................................................... 8

4. TEST MODE.............................................................. 11

5. MECHANICAL ADJUSTMENTS....................... 14

6. ELECTRICAL ADJUSTMENTS

DECK Section ................................................................. 14

CD Section ...................................................................... 17

7. DIAGRAMS

7-1. Block Diagram – CD SERVO Section – ........................ 19

7-2. Block Diagram – TAPE DECK Section –...................... 21

7-3. Block Diagram – MAIN Section –................................. 23

7-4. Block Diagram – DISPLAY/KEY CONTROL/

POWER SUPPLY Section – ........................................... 25

7-5. Note for Printed Wiring Boards and

Schematic Diagrams ....................................................... 27

7-6. Printed Wiring Board – BD Board – .............................. 29

7-7. Schematic Diagram – BD Board – ................................ 31

7-8. Printed Wiring Boards – CD MOTOR Section –.......... 33

7-9. Schematic Diagram – CD MOTOR Section – .............. 35

7-10. Printed Wiring Board – AUDIO Board – ...................... 37

7-11. Schematic Diagram – AUDIO Board – ......................... 39

7-12. Printed Wiring Board – LEAF SW Board –.................. 41

7-13. Schematic Diagram – LEAF SW Board –..................... 41

7-14. Printed Wiring Board – MAIN Board – ........................ 43

7-15. Schematic Diagram – MAIN Board (1/4) – .................. 45

7-16. Schematic Diagram – MAIN Board (2/4) – .................. 47

7-17. Schematic Diagram – MAIN Board (3/4) – .................. 49

7-18. Schematic Diagram – MAIN Board (4/4) – .................. 51

7-19. Printed Wiring Board – PANEL/CD SW Board – ........ 53

7-20. Schematic Diagram

– PANEL (1/3)/CD SW Board – ..................................... 55

7-21. Schematic Diagram – PANEL (2/3) Board – ................ 57

7-22. Schematic Diagram – PANEL (3/3) Board – ................ 59

7-23. Printed Wiring Board – TRANS Board –....................... 61

7-24. Schematic Diagram – TRANS Board –......................... 62

7-25. Printed Wiring Board

– SUB TRANS Board (RXD9) –.................................... 63

7-26. Schematic Diagram

– SUB TRANS Board (RXD9) –.................................... 64

7-27. IC Pin Function Description ........................................... 69

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 for AC leakage.
Check leakage as described below.

LEAKAGE TEST

The A C leaka ge from an y e xposed metal part to earth g round and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microampers.).
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. Follo w 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 low­voltage scale. The Simpson 250 and Sanwa SH-63T rd are e x­amples of a passive VOM that is suitable. Nearly all battery
operated digital multimeters that have a 2 V A C range are suit­able. (See Fig. A)

To Exposed Metal
Parts on Set

AC

1.5 k

0.15 µF

Fig. A. Using an AC voltmeter to check AC leakage.

Ω

Earth Ground

voltmeter
(0.75 V)

8. EXPLODED VIEWS ................................................ 74

9. ELECTRICAL PARTS LIST ............................... 83

– 3 –

SECTION 7

DIAGRAMS

7-1. BLOCK DIAGRAM – CD SERVO Section –

MHC-GRX9900

DETECTOR

A

B

C

D

F

E

OPTICAL PICK-UP
(KSS-213D/Q-NP)

LASER DIODE

PD

7

4

2

1

5

I-V AMP

10

6

LD

CD D+5V

10

11

AUTOMATIC

POWER

CONTROL

Q101

FOCUS/TRACKING ERROR AMP

A

5

B

6

C

7

D

8

F

F I-V AMP

E

E I-V AMP

LD

3

RF AMP,

IC103

SUMMING

APC LD

AMP

RF

AMP

RF EQ

AMP

FOCUS

ERROR AMP

TRACKING

ERROR AMP

APC PD

AMP

RFO

HOLD SW

LDON

FILTER

53

54 56

FILO

PCO

CLTV

RFAC

ASYI
ASYO

DIGITAL

CLV

MDP

26

ASYMMETRY
CORRECTION

XRST

3

16

FE

14

TE

13

21

22

PD

4

51

49
48

DIGITAL

SUBCODE

PROCESSOR

XLON

XLAT

DATA

14 5 6

PLL

CPU INTERFACE

CLOK

SENS
8

7

DIGITAL SIGNAL PROCESSOR,

DIGITAL FILTER, D/A CONVERTER

55

FILI

EFM

DEMODULATOR

SERVO AUTO

SEQUENCER

SQSO

SCOR

20

1 2

16K

RAM

SQCK

IC101 (1/2)

CORRECTOR

SERVO

INTERFACE

SCLK

COUT

9 21

D/A

INTERFACE

INTERNAL BUS

ERROR

SSTP

EMPH

WFCK

GFS

64 15

27

ON :

18

S101

(LIMIT)

When the optical pick-up
is inner position.

PCMD

BCK
LRCK
C2PO

SERIAL

IN

INTERFACE

DIGITAL

62
63
61
19

OUT

DOUT

60

DIGITAL

FILTER,

NOISE SHAPER

TO MIRR/DFCT/
FOK DETECTOR

PWM

&

INTEGRATOR

AOUT1

AOUT2

70

77

CLOCK

GENERATOR

X101

CD DIGITALOUT

OPTICAL
OPTICAL

TRANSCEIVER

CD-L

IC381

IC381

A

(Page 23)

BUFFER

TIMING

LOGIC

LOUT1

LOUT2

XTAI

XTAO

72

75

R-CH

66
67

16.9344MHz

AIN1

71

AIN2

76

(TRACKING)

(FOCUS)

05

2-AXIS
DEVICE

M101

(SPINDLE)

M102

(SLED)

FOCUS/TRACKING COIL DRIVE,

SPINDLE/SLED MOTOR DRIVE

CH4OUTF

15

M

M

16

17
18

12
11

14
13

CH4OUTR

CH3OUTF
CH3OUTR

CH2OUTF
CH2OUTR

CH1OUTF
CH1OUTR

IC102

MOTOR

DRIVE

MOTOR

DRIVE

COIL

DRIVE

COIL

DRIVE

CH4SIN

CH3FIN

CH3RIN

CH2FIN
CH2RIN

CH1FIN
CH1RIN

MUTE

25

43

39

40

41

FE

TE

SE

24
23

SFDR

28

SRDR

29

5
6

2
3

20

TFDR

30

TRDR

31

FFDR

32
33

FRDR

FOCUS/TRACKING/SLED

RFDC

A/D

CONVERTER

PWM GENERATOR

SERVO DSP

FOCUS/TRACKING/SLED

DIGITAL SERVO

PROCESSOR

IC101 (2/2)

MIRR/DFCT/

FOK

DETECTOR

TO SERVO INTERFACE

FOK

MIRR

DFCT

24
22
23

33

SQ-CLK

32

SQ-DATA

19

SCOR

56

SENSE

37

CD-CLK

58

XLT
CD-DATA

35

HOLD

57

SYSTEM CONTROLLER

(CD MECHANISM CONTROL)

IC501 (1/4)

59

XRST

DISC-SENS

TBL-SENS

OUT-OPEN

ENC1
ENC2
ENC3

LOAD-OUT

LOAD-IN

TBL-L
TBL-R

60

61

71

69
68

66
67

63
65

LEVEL SHIFT

Q701

(OPEN/CLOSE DET)

470

ROTARY

2

ENCODER

S811

3

DISC TRAY SLIDE MOTOR DRIVE

FIN

10

RIN

2

DISC TRAY TURN MOTOR DRIVE

IN1

3

IN2

6

DISC TRAY SENSOR

S801

CLOSE

OPEN

IC801

MOTOR

DRIVE

IC701

MOTOR

DRIVE

DISC IN DETECT

SENSOR

IC703

IC702

DISC TRAY

ADDRESS DETECT

OUT1

7

OUT2

4

OUT1

7

OUT2

2

M

(DISC TRAY SLIDE)

M

(DISC TRAY TURN)

M801

M701

– 19 – – 20 –

• SIGNAL PATH
: CD PLAY (ANALOG OUT)
: CD PLAY (DIGITAL OUT)

MHC-GRX9900

7-2. BLOCK DIAGRAM – TAPE DECK Section –

HP101

(PLAYBACK)

L-CH

R-CH R-CH

HRPE101 (1/2)

(RECORD/PLAYBACK)

L-CH

R-CH R-CH

3

R-CH

PB EQ AMP

(DECK A)

IC611

PB EQ AMP

(DECK B)

IC601

REC/PB SWITCHING

IC602

1

R-CH

RV311

PB LEVEL (L)

(DECK A)

RV301

PB LEVEL (L)

(DECK B)

4

DECK PROCESS

DECK A/B SELECT, PB/REC EQ AMP,

DOLBY NR AMP, ALC, AMS

AIN (L)

48

BIN (L)

46

BIAS (N)

33

BIAS (C)

32

BIAS (M)

31

A 120/70

19

S1004

(DECK A 120/70)

S1008

(DECK B 120/70)

IC301

BIAS

CONTROL

CIRCUIT

B NORM/CROM

ALC ON/OFF

NORM/HIGH

PB A/B

1516182022 23242517

70

120

R-CH

NR ON/OFF

BIAS ON/OFF

RM ON/OFF

+

L.P.F.

BUFFER

28

27

AMS

CIRCUIT

REC/PB/PASS

LM ON/OFF

26

MAOUT

MSIN

MSOUT

RIN (L)

43

ALC (L)

44

DOLBY PASS

ALC

ROUT (L)
35 34

DOLBY NR

AMP

CIRCUIT

ALC

IN (L)

REC OUT (L)
39

RV301

REC LEVEL (L)

(DECK B)

EQ IN (L)

38

REC

EQ AMP

PB OUT (L)

EQ OUT

• SIGNAL PATH
: PLAYBACK (DECK A)

40

(L)

36

PB-L

REC-L

B

(Page 23)

C

(Page 24)

: PLAYBACK (DECK B)
: RECORD

RV441

REC BIAS (R)

(DECK B)

HRPE101 (2/2)

(ERASE)

R-CH

05

2

RV341

REC BIAS (L)

(DECK B)

BIAS OSC

T621

BIAS OSC

Q621, 622

REC BIAS

SWITCH

Q623

C331, L331

BIAS

TRAP

B+

(A+7V)

D+5V

100

TC-RELAY

(DECK A PLAY)

8584838281 807978

PB-A/B

EQ-H/N

ALC-ON/OFF

A-PLAY-SW

87

S1001

S1002

(DECK B PLAY)

BIAS

REC-MUTE

B-PLAY-SW

86

TC-MUTE

R/P-PASS

NR-ON/OFF

(DECK A HALF)

S1003

77

AMS-IN

88

DETECT SENSOR

A-HALF

(DECK B HALF)

(DECK A REC)

ROTATION

(DECK A)

IC1001

91

A-SHUT

S1006

S1005

S1009

(DECK B REC)

ROTATION

DETECT SENSOR

(DECK B)

IC1002

90

B-SHUT

SYSTEM CONTROLLER

B-HALF

89

IC501 (2/4)

TRIGGER PLUNGER

DECK A

TRIGGER

PLUNGER DRIVE

(DECK A)

Q333, 334

73

A-TRG

TRIGGER PLUNGER

DECK B

TRIGGER

PLUNGER DRIVE

(DECK B)

Q331, 332

72

B-TRG

Q335

76

CAP-M-H/L

RV1001

TAPE SPEED

(HIGH)

CAPM-CNT1
CAPM-CNT2

CAPSTAN MOTOR

CONTROL SWITCH

Q1001

75

MOTOR DRIVE

74

RV1002

TAPE SPEED

(NORMAL)

CAPSTAN

Q336 – 343

M

M1

(CAPSTAN)

– 21 –

– 22 –

7-3. BLOCK DIAGRAM – MAIN Section –

MHC-GRX9900

J711

MIX MIC

(Page 20)

A

(Page 22)

B

VIDEO

(AUDIO) IN

MD IN

(Page 25)

D

(GRX9900)

FM

75Ω

AM

• SIGNAL PATH
: TUNER (FM/AM)

: CD PLAY
: TAPE PLAY

: RECORD
: MIC INPUT

(Page 25)

E

CD-L

PB-L

J101 (1/2)

L

R

L

R

SPEANA

ANTENNA

RESET

R-CH

R-CH

MIC AMP

IC712 (1/2)

65
66
68
69
67

FM/AM TUNER UNIT

FM ANT

FM ANT

AM ANT

AM ANT

RV712

MIC LEVEL

IN E2
IN D2

INPUT

IN B2

SELECT

IN A2

SWITCH

IN C2

R-CH

INPUT SELECT SWITCH,

GRAPHIC EQUALIZER CONTROL,

ELECTRICAL VOLUME

IC101

ST-L
ST-R

ST-MUTE

STEREO

TUNED
ST-DIN

ST-DOUT

ST-CLK

ST-CE

R

R-CH

05

SOUND

CONTROL

CIRCUIT

X601

32.768kHz

X613

16MHz

MIC AMP

IC712 (2/2)

49
50
51

53
54
55
52

21
20

11

10

13

15

KEY IN2

KEY IN1

KEY OUT 2

60 5 59 6

SYSTEM CONTROLLER

ST-MUTE
STEREO
TUNED

ST-DOUT
ST-DIN
ST-CLK
ST-CE

XC-OUT

XC-IN

X-OUT

X-IN

KEY OUT 1

BASS FREQ.

IC501 (3/4)

PROTECTOR

2 58 57

MIC IN

REC A2

+

+

L+R

+

493-DATA

493-CLK

493-LATCH

DBFB-H/L

STK-MUTE

LINE-MUTE

AC-CUT

RESET

F-RELAY

RY-SW

30

47
48
38

7

44

1

6

22

12

27

3

36

RESET SWITCH

GRAPHIC EQUALIZER

CONTROL CIRCUIT

R-CH

D607
D644

MUTING CONTROL

SWITCH

Q508, 509

Q501

REC B2

F OUT2

42 41

MUTING

Q113

R-CH

COMMAND

+

POWER AMP

STANDBY SWITCH

Q803, 804, 881

+5V

RESET SIGNAL

GENERATOR

IC502

IC801

VOL
IN2

VOLUME

CONTROL

+

R-CH

R-CH

+

CPU

INTERFACE

DATA

CLOCK

LATCH

34

TH831

OVER LOAD

DETECT

Q801

DC DETECT

SWITCH

Q433, 434

BASS BOOST

CONTROL

CIRCUIT

BB B2,

BB A2

38, 39

DBFB CONTROL

SWITCH

Q111

CONTROL SWITCH

TEMPERATURE

DETECT SWITCH

Q831, 832

+

R-CH

SUPER

WOOFER

BUF IN2
373233

BASS FREQUENCY

Q201

R-CH

D803

PROTECT SWITCH

BUF

OUT2

FEED BACK

SWITCH

Q112

R-CH

OVER LOAD

DETECT SWITCH

Q439

72

36

D141

R-CH

MUTING CONTROL

SWITCH

Q412

Q432

R-CH

+

D191

PROTECT

SWITCH

Q192

–1

–2

R-CH

R-CH

OVER LOAD

DETECT SWITCH

Q437

PROTECT SWITCH

Q435, 436

MUTING

Q411, 471

R-CH

MUTING

Q191

RELAY
DRIVE

Q431

J101 (2/2)

J191

SUPER

WOOFER

RY401

REC-L

L

MD OUT

R

FAN MOTOR

DRIVE

Q401, 402

TM401

SPEAKER

IMPEDANCE

USE 6 – 16Ω

+
–

+
–

C

PHONES

(Page 22)

L

R

J701

M501
(FAN)

M

– 23 –

– 24 –

MHC-GRX9900

7-4. BLOCK DIAGRAM – DISPLAY/KEY CONTROL/POWER SUPPLY Section –

D

(Page 23)(Page 23)

E

GRID DRIVE

Q611 – 616

FL601

FLUORESCENT INDICATOR TUBE

GRID DRIVE

Q610

S611 – 630,

S637 – 650, 801 – 807

REMOTE CONTROL

RECEIVER

IC602

LED DRIVE

Q607

LED DRIVE

Q608

D608, 609

ROTARY

ENCODER

S601

ROTARY

ENCODER

S602

S601

(JOG DIAL)

S602

VOLUME

D609

(RIGHT)

D608

(LEFT)

(FOR ILLUMINATION DISPLAY)

FLUORESCENT INDICATOR TUBE DRIVER,

45

10

22

15

05

KEY CONTROL

IC601

S LOW FREQ (BPF0)

46 – 67

S1 – S22

32 – 27

G13 – G18

G2 – G12

44 – 42, 40 – 33

G1

11 – 14

KEY0 – KEY3

1

SIRCS

2

JOG-A

8

JOG-B

VOL-A

9

VOL-B

GRADATION R/WAKE UP

GRADATION L

XOUT

72

X601

12.5MHz

BPF1
BPF2

BPF3
BPF4

ALL BAND (L+R)

RESET

L SEL

LED DATA

LED SCK

LED LAT

I2C DATA

I2C CLK

XIN

70

BAND-PASS FILTER

IC603

16
17
18
19
20

21

73

7

5
3
4

78
79

F01

17

F02

16

F04

14

DET

F05

13

F06

12

L+R

11

DET

LED DRIVER

IC604

DATA

13
14

CLK

15

STB

SYSTEM CONTROLLER

IC501 (4/4)

IIC-DATA

30

IIC-CLK

29

WAKE UP

18

LINE

B.P.F.

17, 19 – 23, 2, 3, 5, 7, 10, 11

P1 – P6, P8, P9, P11, P12, P15, P16

CD-POWER

POWER

STBY LED

TIMER LED

IN

REC IN

42
43

5

2

39

26

LED DRIVE

Q604, 620

LED DRIVE

SPEANA

4

6

B+ SWITCH

Q601, 602

D611 – 615, 619,
D620, 622 – 626,

D631 – 634, 801 – 803

Q605

RESET

LED +5V

Q603

D804

I/u

D636

TIMER SELECT

+5V

SYSTEM CONTROLLER

(IC501) B+

+5V (STBY)

(PANEL SECTION B+)

CD D+5V, CD A+5V

CD MECHANISM DECK

SECTION B+

D+5V

M62493FP (IC101),

CD SENSOR CIRCUIT B+

(RXD9)

D501, 502

D509

B+ SWITCH

Q907, 908

B+ SWITCH

Q904, 905

D+5V

(TAPE DECK SECTION B+)

LED +5V

(PANEL SECTION B+)

(GRX9900)

(RXD9)

D925

(GRX9900)

(RXD9)

D923

(GRX9900)

(RXD9)

D922

(GRX9900)

(RXD9)

D924

(GRX9900)

–26V

(FL DRIVER (IC601) B–)

REGULATOR

TC, PANEL,

REGULATOR

CONTROL SWITCH

Q903, 923

CD M+7V

(CD MOTOR SECTION B+)

TC M+12V

(TC MOTOR SECTION B+)

ST +10V

(FM/AM TUNER UNIT B+)

+5V

IC902

AUDIO

POWER AMP (IC801),
PROTECTOR CIRCUIT

+7V

–7V

FAN MOTOR B–

+10V

REGULATOR

Q909

TO FLUORESCENT

INDICATOR TUBE

(FL601)

REGULATOR

Q901, 902, 913

REGULATOR

Q914, 951, 952

VF1
VF2

B+
B–

B+
B–

–26V REGULATOR

Q971

+7V

–7V

D405 – 407

+7V

REGULATOR

IC901

+12V

REGULATOR

IC903

(GRX9900)

RECT
D832

RECT
D831

RECT
D971

RECT

D901 – 904

RECT

D907 – 910

POWER TRANSFORMER

T951

VOLTAGE

SELECTOR

S951

AC IN

– 25 –

– 26 –

7-5. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS

(In addition to this, the necessary note is printed in each block)

Note on Printed Wiring Board:

•X: parts extracted from the component side.

•Y: parts extracted from the conductor side.

• p : parts mounted on the conductor side.

• ¢ : internal component.

•b: Pattern from the side which enables seeing.

(The other layers' patterns are not indicated.)

Caution:
Pattern face side: Parts on the pattern face side seen from
(Side B) the pattern face are indicated.
Parts face side: Parts on the parts face side seen from
(Side A) the parts face are indicated.

•Indication of transisitor.

Q

B

CE

These are omitted.

Q

B

CE

These are omitted.

C
Q

B

E

These are omitted.

Note on 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 Ω and 1/
specified.

• ¢ : internal component.

•2: nonflammable resistor.

•5: fusible resistor.

•C: panel designation.

Note:The components identified by mark ! or

dotted line with mark ! are critical for safety.
Replace only with part number specified.

•U: B+ Line.

•V: B– Line.

•H: adjustment for repair.

•Voltages are taken with a VOM (Input impedance 10 MΩ).
Voltage variations may be noted due to normal produc­tion tolerances.

•Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc­tion tolerances.

•Circled numbers refer to waveforms.

•Signal path.

F : TUNER (FM/AM)
E : PLAYBACK (DECK A)
d : PLAYBACK (DECK B)
G : RECORD
J : CD PLAY (ANALOG OUT)
c : CD PLAY (DIGITAL OUT)
N : MIC INPUT

•Abbreviation

4

W or less unless otherwise

• Circuit Boards Location

CD SW board

PANEL board

TRANS board

SUB TRANS board
(RXD9)

TUNER PACK

MAIN board

AR : Argentine model

SENSOR board

MOTOR (TURN) board

BD board

CONNECTOR board

MOTOR (SLIDE) board

AUDIO board

– 27 –

LEAF SW board

– 28 –

MHC-GRX9900

7-6. PRINTED WIRING BOARD – BD Board –• See page 28 for Circuit Boards Location.

)(

TP(GND)

TP(VC)

TP(RF)

TP

(AGCCON)

TP(FE)

TP(TE)

TP(FE1)

21

31

31,,

21

05

05

)(

)(

(Page 43)

19

21

21

31

31,,

•Semiconductor
Location
(Side A)

Ref. No. Location

Q101 C-3

KSS-213D/Q-NP

– 29 –

•Semiconductor
Location
(Side B)

Ref. No. Location

IC101 C-2
IC102 B-1
IC103 B-1

– 30 –

7-7.SCHEMATIC DIAGRAM – BD Board – • See page 65 for Waveforms. • See page 66 for IC Block Diagrams.

MHC-GRX9900

(Page 45)

•Voltages and waveforms are dc with respect to ground
under no-signal conditions.
no mark: CD STOP
( ): CD PLAY

The components identified by mark ! or dotted
line with mark ! are critical for safety.
Replace only with part number specified.

– 31 –

– 32 –

MHC-GRX9900

7-8.PRINTED WIRING BOARDS – CD MOTOR Section –• See page 28 for IC Circuit Boards Location.

(Page 43)

B

DISC TRAY

SLIDE

DISC TRAY

TURN

1-658-577-

(DISC TRAY ADDRESS DETECT)

05

C

(Page 43)

– 33 –

– 34 –

7-9.SCHEMATIC DIAGRAM – CD MOTOR Section –• See page 67 for IC Block Diagrams.

DISC TRAY

ADDRESS DETECT

DISC TRAY SLIDE

CLOSE

OPEN

MHC-GRX9900

DISC IN DETECT

SENSOR

DISC TRAY

SENSOR

MTZJ-T-72

(DISC TRAY SLIDE)

DISC
TRAY

TURN

DISC TRAY TURN

MOTOR DRIVER

B

(Page 45)

MTZJ-T-72

C

(Page 45)

LEVEL SHIFT

– 35 –

•Voltages are dc with respect to ground under no-signal
conditions.
no mark: CD STOP

– 36 –

MHC-GRX9900

7-10.PRINTED WIRING BOARD – AUDIO Board –• See page 28 for Circuit Boards Location.

(

)

05

D

(Page 43)

– 37 –

– 38 –

7-11.SCHEMATIC DIAGRAM – AUDIO Board –• See page 68 for IC Block Diagram.

HCD-GRX9900

(PLAYBACK)

PB EQ AMP

(DECK A)

PB EQ AMP

(DECK B)

PB LEVEL (L)

(DECK A)

PB LEVEL (R)

(DECK A)

PB LEVEL (L)

(DECK B)

PB LEVEL (R)

(DECK B)

D

(Page 49)

REC BIAS (R)

(DECK B)

BIAS OSC

REC BIAS (L)

(DECK B)

SWITCHING

REC BIAS

-6.8

•Voltages are dc with respect to ground under no-signal
conditions.
no mark: TAPE PLAY
( ): RECORD

– 39 –

The components identified by mark ! or dotted
line with mark ! are critical for safety.
Replace only with part number specified.

– 40 –

MHC-GRX9900

7-12. PRINTED WIRING BOARD – LEAF SW Board –• See page 28 for Circuit Boards Location.

DECK A

PLUNGER

4

3

1

2

(DECK A PLAY)

05

(DECK A HALF)

(DECK A 120/70)

(

(DECK A REC)

)

7-13. SCHEMATIC DIAGRAM – LEAF SW Board –

(CAPSTAN)

DECK B

PLUNGER

DECK A

PLUNGER

(DECK A 120/70)

(DECK A HALF)

(DECK A REC)

(DECK B HALF)

ROTATION DETECT SENSOR

(DECK A)

CONTROL SWITCH

ROTATION DETECT

SENSOR (DECK B)

E

(Page 43)

(DECK B PLAY)

4

1

(DECK B HALF)

DECK B

PLUNGER

3

2

(DECK B 120/70)

(DECK B REC)

21
21

•Semiconductor Location

Ref. No. LocationRef. No. Location

D141 E-10
D191 E-12
D331 E-1
D333 F-1
D334 E-1
D335 F-1
D401 G-11
D403 F-12
D405 H-6
D406 J-4
D407 I-2
D411 G-3
D501 D-7
D502 E-6
D503 D-6
D504 D-7
D505 D-7
D506 D-7
D509 F-2
D607 E-5
D644 C-8
D801 J-11
D802 G-9
D803 G-11
D831 I-6
D832 J-7
D851 J-10
D852 G-9
D881 H-9
D901 J-4
D902 J-4
D903 J-4
D904 I-4
D905 I-1
D906 H-1
D907 J-5
D908 I-5
D909 J-5
D910 J-5
D915 I-4
D921 H-4
D922 G-4
D923 G-4
D924 F-2
D925 G-4

Q113 E-9
Q161 C-9
Q162 C-9
Q163 E-9
Q191 E-12
Q192 E-10
Q201 D-9
Q251 C-9
Q331 C-1
Q332 C-2
Q333 C-2
Q334 C-2
Q335 D-1
Q336 F-1
Q337 F-1
Q338 F-1
Q339 F-1
Q340 E-1
Q341 E-1
Q342 F-1
Q343 E-1
Q401 F-12
Q402 E-12
Q411 G-2
Q412 G-3
Q431 G-12
Q432 G-11
Q433 F-11
Q434 F-11
Q435 F-11
Q436 F-11
Q437 G-12
Q439 F-12
Q471 F-2
Q501 D-7
Q508 D-7
Q509 E-7
Q801 H-10
Q803 G-10
Q804 G-9
Q831 G-10
Q832 G-10
Q851 J-10
Q881 I-9
Q901 H-2
Q902 I-1
Q903 H-1
Q904 G-4
Q905 G-4
Q907 G-5
Q908 G-4
Q909 I-4
Q913 H-1
Q914 G-2
Q923 H-1
Q951 G-2
Q952 H-1

E

(Page 49)

IC101 C-10
IC301 B-3
IC381 A-12
IC501 D-5
IC502 D-7
IC801 H-10
IC901 G-6
IC902 G-4
IC903 H-4

Q111 D-10
Q112 D-10

(DECK B REC)

(DECK B 120/70)

•Voltages are dc with respect to ground under no-signal
conditions.
no mark: TAPE PLAY
( ): RECORD

: Impossible to measure

∗

– 41 –

(DECK A PLAY)

(DECK B PLAY)

– 42 –

7-14.PRINTED WIRING BOARD – MAIN Board –• See page 28 for Circuit Boards Location.

MHC-GRX9900

(Page 38)

(Page 41)

(Page 33)(Page 33)

(Page 30)

(Page 53)
(Page 61)

(GRX9900)

(RXD9)

(Page 63)

(Page 61)

– 43 – – 44 –

MHC-GRX9900

7-15. SCHEMATIC DIAGRAM – MAIN Board (1/4) –

•Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark: TUNER (FM/AM)
( ): CD PLAY

(Page 31)

(Page 36)

(Page

47)

(Page

51)

(Page 36)

(Page 50)

– 45 –

– 46 –

7-16.SCHEMATIC DIAGRAM – MAIN Board (2/4) –

MHC-GRX990

(Page

46)

(Page

50)

(Page 61)

(Page 52)

•Voltages are dc with respect to ground under no-signal
(detuned) conditions.
no mark: FM

– 47 –

The components identified by mark ! or dotted
line with mark ! are critical for safety.
Replace only with part number specified.

– 48 –