Sony XR-4800 Service manual

XR-4790/4800

SERVICE MANUAL

Photo: XR-4800

SPECIFICATIONS

AUDIO POWER SPECIFICATIONS (US model)

POWER OUTPUT AND TOTAL HARMONIC DISTORTION 13 watts per channel minimum continuous average power into 4 ohms, 4 channels driven from 20 Hz to 20 kHz with no more than 1% total harmonic distortion.

Cassette player section

Tape track 4-track 2-channel stereo Wow and flutter 0.08% (WRMS) Frequency response 30 – 18,000 Hz Signal-to-noise ratio 58 dB

Tuner section

Tuning range FM tuning interval:

87.5 – 107.9 MHz (XR-4790, XR-4800: US, Canadian model) 50 kHz/200 kHz switchable

87.5 – 108.0 MHz (at 50 kHz step)

87.5 – 107.9 MHz (at 200 kHz step)

(XR-4800: E model) Antenna terminal External antenna connector Intermediate frequency 10.7 MHz Usable sensitivity 8 dBf Selectivity 75 dB at 400 kHz Signal-to-noise ratio 65 dB (stereo),

68 dB (mono) Harmonic distortion at 1 kHz

0.5% (stereo),

0.3% (mono) Separation 35 dB at 1 kHz Frequency response 30 – 15,000 Hz Capture ratio 2 dB

US Model

Canadian Model

XR-4800

E Model

XR-4790/4800

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

AM (MW)

Tuning range AM tuning interval:

530 – 1,710 kHz (XR-4790, XR-4800: US, Canadian model) MW tuning interval: 9 kHz/10 kHz switchable 531–1,602 kHz (at 9 kHz step) 530 – 1,710 kHz (at 10 kHz step)

(XR-4800: E model) Antenna terminal External antenna connector Intermediate frequency 10.71 MHz/450 kHz. Sensitivity 30 µV

SW (XR-4800: E model)

Tuning range SW tuning interval:

SW1: 2,940 – 7,735 kHz

SW2: 9,500 – 18,135 kHz

(except for 10,140 – 11,575 kHz) Antenna terminal External antenna connector Intermediate frequency 10.71 MHz/450 kHz Sensitivity 50 µV

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XR-4790, XR-4800: US, Canadian Model

FM/AM CASSETTE CAR STEREO

XR-4800: E Model

MICROFILM

FM/MW/SW CASSETTE CAR STEREO

Power amplifier section

Outputs Speaker outputs

(sure seal connectors)

Speaker impedance 4 – 8 ohms Maximum power output 35 W × 4 (at 4 ohms)

General

Outputs Power antenna control

lead/Power amplifier control lead/Telephone ATT control lead (E model only) Rear line out (1)

Tone controls Bass ± 8 dB at 100 Hz

Treble ± 8 dB at 10 kHz

Power requirements 12 V DC car battery

(negative ground)

Dimensions Approx. 188 × 58 × 181 mm

(7 1/2 × 2 3/8 × 7 1/4 in.) (w/h/d)

Mounting dimensions Approx. 182 × 53 × 164 mm

(7 1/4 × 2 1/8 × 6 1/2 in.)

(w/h/d) Mass Approx. 1.2 kg (2 lb. 10 oz.) Supplied accessories Parts for installation and connections (1 set)

Front panel case (1)

Design and specifications are subject to change without notice.

TABLE OF CONTENTS

1. GENERAL

Location of Controls (XR-4790) .................................... 3

Location of Controls (XR-4800) .................................... 4

Resetting the Unit ........................................................... 5

Detaching the Front Panel............................................... 5

Setting the Clock ............................................................. 5

Installation (US, Canadian model) ................................. 6

Installation (E model) ..................................................... 7

Connection ...................................................................... 8

2. DISASSEMBLY ......................................................... 10

3. ASSEMBLY OF MECHANISM DECK............ 12

4. MECHANICAL ADJUSTMENTS ....................... 15

5. ELECTRICAL ADJUSTMENTS

Test Mode........................................................................ 15

Tape Deck Section .......................................................... 15

Tuner Section .................................................................. 16

6. DIAGRAMS................................................................. 19

6-1. Printed Wiring Board –MAIN Section–........................ 21

6-2. Schematic Diagram –MAIN Section– ........................... 23

6-3. Printed Wiring Board –PANEL Section– (XR-4790) ... 27

6-4. S c hematic Diagram –PANEL Section– (XR-4790) ...... 29

6-5. Pr inted Wiring Board –PANEL Section– (XR-4800) .... 31

6-6. S c hematic Diagram –PANEL Section– (XR-4800) ...... 33

6-7. IC Pin Function Description ........................................... 35

7. EXPLODED VIEWS ................................................ 38

8. ELECTRICAL PARTS LIST ............................... 42

Flexible Circuit Board Repairing

• Keep the temperature of the 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 chip component replacement

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be damaged by heat.

– 2 –

SECTION 1

GENERAL

This section is extracted from instruction manual.

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– 5 –

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– 8 –

(E model only)

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SECTION 2

DISASSEMBLY

Note: Follow the disassembly procedure in the numerical order given.

FRONT PANEL ASS’Y

1

Push the button (release).

COVER ASS’Y

2

Remove the front panel ass’y to the direction of the arrow

cover ass’y

3

– 10 –

SUB PANEL, MECHANISM DECK (MG-25F-136)

3

connector (CN351)

2

sub panel

1

three screws (PTT2.6

5

screw (PTT2.6

4

flexible flat cable (CN301)

6

mechanism dec (MG-25F-136)

1

three screws (PTT2.6

MAIN BOARD, HEAT SINK

3

two ground point screws

4

main board

5

two screws (PTT 2.6

2

rubber cap (25)

1

5

three screws (PTT 2.6

6

heat sink

two screws (PTT2.6

5

two screws (PTT 2.6

10)

1

screw (PTT2.6

– 11 –

SECTION 3

ASSEMBLY OF MECHANISM DECK

Note: Follow the assembly procedure in the numerical order given.

5

HOUSING

3

Put the housing under

2

4

Fit claw on B part.

part.

housing

Install the hanger onto two claws of the housing.

Fit projection on C part.

part

7

Holder the hanger by bending the claw.

1

Install the catch to the hanger.

hanger

6

Fit projaction on D part.

8

Hold the hanger by bending the claw.

part

ARM (SUCTION)

part

projection

part

2

Move the arm (suction) in the arro direction and fit on projection.

1

Fit the arm (suction) on the shaft.

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+ 26 hidden pages