Sony XR-4880 Service Manual

XR-4880

SERVICE MANUAL

Photo: XR-4880

SPECIFICA TIONS

AEP Model

UK Model

Model Name Using Similar Mechanism XR-C6100R Tape T ransport Mechanism T ype MG-25F-136

MICROFILM

FM/MW/LW CASSETTE CAR STEREO

+

–

+

–

+

–

+

–

OVER VOLTAGE

PROTECT

REGULATOR

1

2 3

4

5 6 7 8 9 10 1211

NC

STB

VDD

AMP

VCC

ANT

COM

AM

FM

GND

SECTION 6

DIAGRAMS

• IC Block Diagrams – MAIN Board –

IC21 TB2118F (EL)

A-GND

VCC

REG

XI

24 23 22 21 20 19

AM CP OUT

VT

+

OSCILLATOR

1

XO

VCC

–

REGULATOR

REFERENCE

DIVIDER

SEEK/RECP

COMPARATOR

SEEK/RECP

ON/OFF

BUFFER

2 345 6 7 8 9 10

OSC

+

PHASE

REF

–

+

40BIT SHIFT

REGISTER

INTERFACE

CE

FM CP OUT

18

SIG

18BIT

SERIAL

DIN

D-GND

17 16 15

4BIT SWALLOW

COUNTER

PRESCALLER

12BIT

PROGRAMMABLE

COUNTER

CK

DOUT

IC301 CXA2509AQ-T4

IC351 LB1930M-TLM

MSSW

NC

LINEOUT2

MSLPF

NR BIAS

TAPE/AUX

TAPE EQ

FWD/RVS

VCC

+ –

F3

–

+

LINEOUT1

DIREF

24dB

NC

24dB

G2FB

2122232627282930

MS

MODE

DETECT

MS ON/

OFF

20

19

18 17

16

15

14

13

12

11

MSMODE

DRSW

TAPESW INSW

NC

MSOUT

DGND

MSTC

G1FB

2425

+

–

NC

AUXIN2

NC

VCC

IN1

IN2

S-GND

1

BUFFER

NC

2

3

4

BUFFER

5

CONTROL

CIRCUIT

MOTOR

DRIVE

CIRCUIT

AMP

AM IN

AMP

FM IN

14 13

VDD

AMP

VDD

IFC

+

20BIT

IF COUNTER

22BIT

I/O

OUTPUT

PORT

SR

I/O-1

I/O-2

PORT

OUT-1

11

OUT-2

VDD2

12

VDD2

10

OUT1

9 8

NC

7

OUT2

P-GND

6

PBFB2

PBRIN2

PBREF2

PBFIN2

VCT

PBGND

PBFIN1

PBREF1

PBRIN1

PBFB1

PBEQ2

–

31 32

33

34

35

VCT

36

37

38

39 40

1

PBEQ1

TAPEIN2

PBOUT2

GND

120µ/70µ

+

F2

F1

–

+

120µ/70µ

345 6 7 8 9 10

2

VCC

PBOUT1

X1

+

X1

TAPEIN1

T2

LPF

T1

AUXIN1

IC661 BA3918-V2

IC331 TDA7462D

SE1L

1

SE1R

2

MD+

3

MD–

4 5

CDL+ CDL–

6

CDR–

7

CDR+

8

PDR

9

PDGND

10

PDL

11

SE2L

12

SE2R

13

CREF

14

FRONT SIDE

MIXING STAGE

INPUT MULTIPLEXER &

REAR SIDE

SELECTOR

INPUT

GAIN &

AUTO ZERO

INPUT

GAIN

PAUSE

DETECT

BEEP

LOUDNESS

CONTROL

CIRCUIT

LOUDNESS

CONTROL

CIRCUIT

VOLUME

CONTROL

CIRCUIT

COMPANDER

DIGITAL CONTROL CIRCUIT

SOFT

MUTE

TREBLE/

BASS

CONTROL

CIRCUIT

VOICE BANDPASS

HP LP

SUBWOOFER

LP

FADER

SUBWOOFER

OUT

IIC

BUS

FRONT FADER

REAR

FADER

REAR

FADER

SDA

SCL

POWER SUPPLY

28 27 26 25 24 23

22

21

20

19

18

17

16

15

SE3L SE3R MUTE SDA SCL PAUSE

OUT FL

OUT FR

OUT RL

OUT RR

SUBOUT+

SUBOUT–

VDD

GND

IC751 TDA7385

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

IN1

IN2

IN4

TAB

PW-GND

OUT2–

ST-BY

OUT2+

Vcc1

OUT1–

PW-GND1

OUT1+

SVR

S-GND

IN3

OUT3+

AC-GND

PW-GND3

OUT3–

Vcc2

OUT4+

MUTE

OUT4–

PW-GND4

DIAGNOSTICS OUT

– 17 – – 18 –

6-2. SCHEMATIC DIAGRAM — MAIN (1/2) SECTION —

• Refer to page 17 for IC Block Diagrams.

• Refer to page 29 for IC Pin Function Description.

XR-4880

FAE342-E01

• Wavef orms

1

2.8Vp-p

18.432MHz

IC501 !™

OSC2

2

5.0Vp-p

32.768MHz

IC501 !§

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.

¢

•

• C : panel designation.

• U : B+ Line.

• Pow er voltage is dc 14.4V and fed with regulated dc po wer

• Voltage and waveforms are dc with respect to ground

• V oltages are taken with a VOM (Input impedance 10 MΩ).

• Waveforms are taken with a oscilloscope.

• Circled numbers refer to waveforms.

• Signal path.

: internal component.

supply from ACC and BATT cords. under no-signal conditions.

no mark : FM < > : TAPE PLAYBACK

Voltage variations may be noted due to normal production tolerances.

F : FM f : AM (MW) E : TAPE PLA YBACK

: Impossible to measure

∗

XO

4

W or less unless otherwise

(FL)

A (OFF) → B (ON)

(Page 23, 24)

– 21 –

– 22 –