SONY CFS 828SMK2 Service Manual

CFS-828SMK2

SERVICE MANUAL

Ver 1.0 2003.12

SPECIFICATIONS

Frequency range

FM: 87.5 - 107 MHz MW: 530 - 1,605 kHz SW1: 2.3 - 7 MHz SW2: 7 - 22 MHz

IF

FM: 10.7 MHz MW/SW: 455 kHz

Antennas

FM/SW: T elescopic MW: Built-in ferrite bar

Recording system

4-track, 2-channel stereo

Frequency response

80 - 12,500 Hz

Speakers

Full range: 10 cm (4 inches) dia., 6 Ω, cone type/ Tweeter: 2 cm (13/16 inches) dia.

Output

Headphones jack (stereo minijack), for 16 - 68 Ω impedance headphones

Maximum Power output

9W

E Model

Model Name Using Similar Mechanism CFS-828S Tape T ransport Mechanism T ype MF-W828-117

Battery life

FM Recording: Sony R20P: Approx. 9 hours/ Sony LR20 alkaline: Approx. 23 hours Playback: Sony R20P: Approx. 3 hours/ Sony LR20 alkaline: Approx. 8 hours

Power requirements

110 - 120 V/220 - 240 V AC selectable, 50/60 Hz 9 V DC, six R20 (size D) batteries DC IN 12V jack

Power consumption

AC 18 W

Dimensions

Approx. 679 × 263.5 × 239.5 mm (w/h/d) (26 6/8 × 10 3/8 × 9 4/9 inches) incl. projecting parts and controls, not incl. handle

Mass

Approx. 7.3 kg (16 lb 1 oz) incl. batteries

Supplied accessory

AC power cord (1)

Design and specifications are subject to change without notice.

9-961-447-01

RADIO CASSETTE-CORDER

Sony Corporation

Personal Audio Company Published by Sony Engineering Corporation

1

CFS-828SMK2

• 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.

7. EXPLODED VIEWS

7-1. Cabinet (Rear) Section ...................................................... 23

7-2. Cabinet (Front) Section-1.................................................. 24

7-3. Cabinet (Front) Section-2.................................................. 25

7-4. Mechanism Deck Section-1 .............................................. 26

7-5. Mechanism Deck Section-2 .............................................. 27

7-6. Mechanism Deck Section-3 .............................................. 28

7-7. Speaker Section .................................................................29

8. ELECTRICAL PARTS LIST........................................30

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.

SAFETY-RELATED COMPONENT WARNING!!

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 PUBLISHED BY SONY.

2

SECTION 1

GENERAL

Location of controls

CFS-828SMK2

This section is extracted from instruction manual.

VOLUME

Deck A

Deck B

MIC

OPR/BATT

FUNCTION

FINE TUNING

BAND

TUNING

PHONES

SOUND SELECT

ISS (rear)

DC IN 12V (rear)

MAXI BASS

VOLTAGE SELECTOR (rear)

3

CFS-828SMK2

)

SECTION 2

DISASSEMBLY

• The equipment can be removed using the following procedure.

SET

2-1. CABINET (FRONT) ASSY,

CABINET (REAR) ASSY (Page 4)

2-2. POWER AND

DC IN BOARDS (Page 5)

2-6. JOG AND LED1

BOARDS

2-4. H/P, LED2, MAXI BASS,

VOL AND MAIN BOARDS (Page 6)

2-5. F/T AND TUNER BOARDS

(Page 6)

(Page 7)

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

2-1. CABINET (FRONT) ASSY, CABINET (REAR) ASSY

qs

cabinet (rear) assy

8

0

CNP311

CNP314

2-3. MECHANISM DECK

(Page 5)

2-7. REC SW BOARD, BELT AND

MOTOR ASSY (W) (M301) (Page 7)

4

three

(+BVTP 3

screws

x

16)

3

screw

(+BVTP 3

x

16)

9

CNP319

1

battery case lid

2

three

screws

x

16

qa

cabinet (front) assy

5

7

CNP318

6

CNP1

(+BVTP 3

4

2-2. POWER AND DC IN BOARDS

cabinet (rear) assy

1

CNP901

3

two

screws

x

(+BVTP 2.6

6

shield plate (T)

5

two

screws

(+BVTP 3

x

10)

8)

4

DC IN board

2

CNP313

7

screw

(+BVTP 3

x

CFS-828SMK2

10)

2-3. MECHANISM DECK

9

two

screws

(+BVTP 3

x

10)

8

two

screws

(+BVTP 3

9

two

(+BVTP 3

x

10)

screws

1

CNP316

0

POWER board

x

10)

0

three

(+BVTP 3

screws

qa

(+BVTP 3

qs

mechanism deck

x

two

10)

screws

x

10)

8

7

2

CNP315

6

CNP306

3

CNP302

4

CNP301

5

CNP305

5

CFS-828SMK2

)

2-4. H/P, LED2, MAXI BASS, VOL AND MAIN BOARDS

4

H/P board

qj

VOL board

5

screw

1

knob (VOL)

qk

claws

6

CNP307

claws

(+BVTP 3

LED2 board

x

10)

3

retainer board

2

screw

(+BVTP 3

qd

CNP417

x

10)

qf

screw

(+BVTP 3

qs

9

MAXI BASS board

x

CNP418

qa

CNP303

qh

7

(+BVTP 3

8

retainer board

ql

10)

MAIN board

screw

x

10

qg

claws

2-5. F/T AND TUNER BOARDS

2

two

screws

(+BVTP 3

x

6

10)

0

button (M. B)

chassis (TUNE)

9

screw

(+P 2.6

4

screw

(+BVTP 3

5

(+BVTP 3

x

4)

two

x

screws

10)

x

10

0

gear (VC)

3

F/T board

qa

1

knob (FT)

knob (BAND)

7

three

(+BVTP 3

screws

x

10)

8

TUNER board

6

2-6. JOG AND LED1 BOARDS

)

3

JOG board

2

two

screws

(+BVTP 3

x

10)

6

window (LED)

4

(+BVTP 3

5

LED1 board

two

CFS-828SMK2

screws

x

10)

1

jog dial

2-7. REC SW BOARD, BELT AND MOTOR ASSY (W) (M301)

deck A

7

belt

0

three motor

4

two

(+PTT 2

6

chassis (SUB)

screws

x

5)

3

screw

(+PTT 2

x

5)

deck B

5

two

screws

(+PTT 2

x

5)

qa

motor assy (W) (M301)

1

screw

(+PTT 2

2

REC SW board

x

5)

9

rever (REC

8

belt

7

CFS-828SMK2

pointer

2

knob (TUN) assy

SECTION 3

DIAL POINTER SETTING

3

midway gear

knob (TUN) assy

midway gear

4

screw

(+BVTP 3

x

1

10)

pointer

UP

5

screw

8

F/T board

3

9

two

screws

(+BVTP 3

x

10)

2

7

screw

(+BVTP 3

x

10)

(+BVTP 3

1

4

TUNER board

x

gear (VC)

6

(+BVTP 3

10)

screw

x

10)

8

SECTION 4

PHONES jack (J301)

set

32

Ω

test tape WS-48A (3 kHz, 0 dB)

digital frequency counter

MECHANICAL ADJUSTMENTS

CFS-828SMK2

SECTION 5

ELECTRICAL ADJUSTMENTS

PRECAUTION

1. Clean the following parts with a denatured alcohol-moistened swab :

record/playback head pinch roller erase head rubber belts capstan idlers

2. Demagnetize the record/playback head with a head demagnetizer. (Do not bring the head demagnetizer close to the erase head.)

3. Do not use a magnetized screwdriver for the adjustments.

4. After the adjustments, apply suitable locking compound to the parts adjusted.

5. The adjustments should be performed with the rated power supply voltage unless otherwise noted.

6. Power supply voltage: 9 V dc.

Torque Measurement DECK A DECK B

Mode Torque meter Meter reading

2.21 to 5.39 mN • m

Forward CQ-102C 22.5 to 55 g • cm

(0.31 to 0.76 oz • inch)

Forward back tension

Fast Forward 5.89 to 11.76 mN • m and CQ-201B 60 to 120 g • cm Rewind (0.83 to 1.67 oz • inch)

Tape Tension Measurement DECK A DECK B

Mode Tension meter Meter reading

Forward CQ-403A

CQ-102C 2 to 5 g • cm

0.20 to 0.49 mN • m

(0.03 to 0.07 oz • inch)

more than 150 g

(more than 5.29 oz)

TAPE SECTION 0 dB = 0.775 V

Standard Output Level

Output terminal SP OUT PHONES OUT

load impedance 6 Ω 32 Ω

output signal level 0.775 V (0 dB) 0.25 V (–10 dB)

Test T ape

Tape Signal Used for

WS-48A 3 kHz, 0 dB tape speed adjustment

Tape Speed Adjustment DECK A DECK B

Procedure:

• Perform normal speed adjustment before high speed check. Mode: playback (deck A)

record (deck B)

Adjust RV301 so that reading on digital frequency counter becomes 3,000 Hz.

Specification V alue:

Deck

A Normal (playback) RV302 2,910 to 3,090 Hz A HI-SPEED DUBBING

B HI-SPEED DUBBING

Tape Adjustment Frequency

speed point counter

(playback)

(record)

(confirmation)

——— ———

5,820 to 6,180 Hz

Frequency difference between the beginning and the end of the tape should be within ± 1.0% (both Normal and Hi-speed).

Adjustment Location: – main board (component side) –

– MAIN board (component side) –

RV302

9

CFS-828SMK2

e

)

TUNER SECTION 0 dB = 1 µV

Common Setting:

SOUND SELECT control: FLAT VOLUME control: MAX MAXI BASS switch: OFF

• FM Section

BAND switch: FM

FM RF signal generator

75kHz frequency deviation by 1kHz signal Output level: as low as possible

• MW Section

BAND switch: MW FINE TUNING (RV2): mechanical center

AM RF signal generator

400Hz, 30% AM modulation Output level: as low as possible

telescopic antenna terminal

0.01µF

Put the lead-wir antenna close to the set.

set

FM IF ADJUSTMENT

Adjust for a maximum reading on level meter.

L9 10.7 MHz

FM FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L2 86.5 MHz

CT2 109.5 MHz

FM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L1 86.5 MHz

CT1 109.5 MHz

MW IF ADJUSTMENT

Adjust for a maximum reading on level meter.

T1 455 kHz

MW FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L4 520 kHz

CT4 1,680 kHz

MW TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L3 600 kHz

CT3 1,400 kHz

• SW1/SW2 Section

BAND switch: SW1 or SW2 FINE TUNING (RV2): mechanical center

AM RF signal generator

400Hz, 30% AM modulation Output level: as low as possible

telescopic antenna terminal

12pF

• Common Connecting Level Meter

32 Ω

set

PHONES jack (J301)

set

level meter (range: 0.5–5 V ac

SW1 FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L6 2.2 MHz

CT6 7.3 MHz

SW1 TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L5 2.2 MHz

< confirmation > 7.3 MHz

SW2 FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L8 6.8 MHz

CT8 22.5 MHz

SW2 TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L7 6.8 MHz

< confirmation > 22.5 MHz

Adjustment Location: See page 11

•Repeat the procedures in each adjustment several times, and the frequency coverage and tracking adjustments should be finally done by the trimmer capacitors.

10

FM VCO Adjustment

y

Y

Setting:

BAND switch: FM

FM RF signal generator

98MHz frequency deviation by 1kHz signal Output level: 0.1V (100dB)

CFS-828SMK2

telescopic antenna terminal

0.01µF set

digital frequenc counter

TUNER board

4

IC1 pin

7

33k

1µF

Ω

Procedure:

1. Connect the frequency counter to pins 4 and 7 of IC1 as shown the figure.

2. Tune the set to 98 MHz.

3. Adjust RV1 for 76 kHz reading on the frequency counter.

Specification Value: 75.95 to 76.05 kHz.

Adjustment Location: – tuner board (component side) –

– TUNER board (component side) –

L3

L9

FM IF

ADJUSTMENT

RV1

FM VCO

ADJUSTMENT

CT2, L2

FM FREQUENCY

COVERAGE

ADJUSTMENT

T1

MW IF

ADJUSTMENT

L9

30

1

IC1

1615

T1

CT1, L1

TRACKING

ADJUSTMENT

RV1

L2

CT2

CT1

CT3

L1

FM

CT4

L8

CT6

L6

CT8

L5

L7

ANT1

FM/SW

TELESCOPIC

ANTENNA

CNP1

L4

L7

SW2

TRACKING

ADJUSTMENT

CT6, L6 SW1 FREQUENCY COVERAGE ADJUSTMENT

CT4, L4 MW FREQUENCY COVERAGE ADJUSTMENT

CT8, L8 SW2 FREQUENC COVERAGE ADJUSTMENT

L5 SW1 TRACKING ADJUSTMENT

CT3, L3 MW TRACKING ADJUSTMENT

11

CFS-828SMK2

6-1. CIRCUIT BOARDS LOCATION

SECTION 6

DIAGRAMS

BATT (–) board

TUNER board

VOL board

MAIN board

BATT (+) board

DC JACK HOLD board (not supplied)

DC IN board

POWER board

LED1 board

LED2 board

H/P board

RETAINER board (not supplied)

JOG board

F/T board

RETAINER board (not supplied)

MAXI BASS board

REC SW board

12

SONY CFS 828SMK2 Service Manual

TABLE OF CONTENTS

GENERAL

DISASSEMBLY

mechanism deck

DIAL POINTER SETTING

MECHANICAL ADJUSTMENTS

ELECTRICAL ADJUSTMENTS

DIAGRAMS