Sony SRFM-95 Service manual

SRF-M95

SERVICE MANUAL

Ver 1.2 2002. 05

SPECIFICATIONS

Time display: 24-hour system Frequency range:

Band Frequency range Channel step

Panama model :

FM AM 530 -1 710 kHz 10 kHz

Except Panama, Tourist model :

FM 87.5 - 108 MHz 0.05 MHz AM 531 -1 602 kHz 9 kHz

Tourist model :

FM 76.0 - 108 MHz 0.05 MHz AM 531 -1 710 kHz 9 kHz

Output: 2 (headphones) jack (∅ 3.5 mm, stereo

minijack)

Power output: 2.5 mW + 2.5 mW (at 10 % harmonic

distortion)

Power requirements: 1.5 V DC, one R03 (size AAA)

battery

87.5 - 108 MHz 0.1 MHz

Battery Life (Approx. hours) When using FM AM

Sony alkaline LR03(size AAA) 40 54 Sony R03(size AAA) 18 26

Auto Power off function: Approx. 30 minutes, 60 Dimensions: Approx. 39 × 83.8 × 20.4 mm (w/h/d)

Mass: Approx. 57.5 g (2 oz.) incl. battery and the

Accessories supplied

Stereo headphones (1)

Design and specifications are subject to change without notice.

Chinese Model

Australian Model

Tourist Model

minutes, 90minutes, 120 minutes, and off

(Approx. 1 projecting parts and controls

headphones

9

/16 × 3 3/8 × 13/16 inches) incl.

AEP Model

E Model

9-873-067-13

FM STEREO/AM PLL SYNTHESIZED RADIO

Sony Corporation

Personal Audio Company Published by Sony Engineering Corporation

SRF-M95

SECTION 1

GENERAL

This section is extracted from instruction manual.

Front Face avant Parte frontal

Display Window Afficheur Visualizador

2

VOL POWER

Jog Lever (selection/decision) Molette (sélection/décision) Palanca de lanzadera (selección/decisión)

MODE

HOLD

MEGA BASS

Setting the Clock

The time display of this clock is a 24-hour system.

1

Press POWER to turn off the power.

2

Press and hold down the jog lever for more than 2 seconds until “0”starts flashing.

3

Slide or keep sliding the jog lever up or down to adjust the hour and press the jog lever.

If you keep sliding the jog lever up or down, the number changes rapidly. 0:00=midnight, 12:00=noon.

4

Slide the jog lever up or down to adjust the minutes and press the jog lever.

“:” starts flashing and the clock starts operating.

To set the current time exactly to the second, adjust the minute and then press the jog lever in time with a time signal (such as the telephone time signal). To cancel the setting, press MODE.

Note

Once you start setting the clock, you must perform each step within 60 seconds, or the clock setting mode will be cancelled.

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

Flexible Circuit Board Repairing

• Keep the temperature of 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.

SECTION 2

)

DISASSEMBLY

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

2-1. MAIN BOARD, SUB BOARD

9

SUB board

7

Cover (Jack)

8

Screw

1

Screw (1.4 × 10)

1

Screw (1.4 × 10)

1

Screw (1.4 × 10

SRF-M95

2

Six claws

3

Cabinet (front) assy

6

MAIN board

4

Screw

5

Flexible board

3

SRF-M95

)

r

SECTION 3

ADJUSTMENTS

AM Section

Setting:

BAND switch: AM

Connection:

For AM frequency coverage adjustment and FM frequency coverage check.

digital voltmeter

TP (VT

Connection:

Put the lead-wire AM RF signal generator

30% amplitude modulation by 400 Hz signal. Output level: as low as possible

antenna close to

the set.

set

level mete

16

Ω

+ –

headphone jack (

FM Section

Setting:

BAND switch: FM FM SENS switch: DX

Connection:

FM RF signal generator

22.5 kHz frequency deviation by 400 Hz signal. Output level: as low as possible

0.01 µF TP (ANT)

( ) : Panama model [ ] : Tourist model

AM FREQUENCY COVERAGE ADJUSTMENT

Adjust for a reading on digital voltmeter.

T201 531 kHz (530 kHz) [531 kHz] 1.3V ± 0.1V

Confirm 1,602 kHz (1,710 kHz) [1,710 kHz] 10 V or less

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

CT201 1485 kHZ (1480 kHz)

L201 585 kHz (590 kHz)

FM FREQUENCY COVERAGE CHECK

Check a reading on digital voltmeter. Confirm 87.5 MHz [76.0 MHz] Confirm 108.0 MHz 11V or less

FM TRACKING ADJUSTMENT

i

)

Adjust for a maximum reading on level meter.

CT101, CT102 108.0 MHZ

L104 87.5 MHz [76.0 MHz]

3.5V [0.9 V] or more

FM VCO Adjustment

Setting:

BAND switch: FM FM SENS switch: DX

Procedure:

1. Turn off the FM RF signal generator.

2. Put a capacitor (100 µF) between pin ws (IC201) and GND.

3. Put a resistor (100 kΩ) between TP (VCO) and GND.

4. Tune the set to 87.5 MHz.

5. Adjust RV201 for 19 kHz ± 0.05kHz reading on the frequency counter.

Connection:

frequency counter

Adjustment Location

[MAIN BOARD]

(SIDE B)

CT101

FM TRACKING Adjustment

AM TRACKING Adjustment

L104

CT102

CT201

L201

TP (VCO)

[MAIN BOARD]

(SIDE A)

IC401

GND

T201

IC101

AM FREQUENCY COVERAGE Adjustment

RV201 FM VCO Adjustment

TP(VCO)

GND

IC201

TP(ANT)

CN401

TP(VT)

GND

TP(pin

ws

)

4

4-1. BLOCK DIAGRAM

SECTION 4

DIAGRAMS

SRF-M95

Ver 1.1 2002. 02

EXCEPT

JE

MODEL

Q101

LOCAL

/DX

FM FRONT END

IC101

RF IN

1

MIX

RF OUT

FM/AM RF,IF AMP

FM IF IN

AM IF IN

MIX OUT

AM RF

AM OSC

DET OUT PILOT IN MPX IN

LPF 2A LPF 2B

LPF1

IC201

L OUT

R OUT

QUAD

VCO

14

15

7

17

TU VCC

CF203

10.7MHz

RV201

VCO

Q102

6

D101

8

D102

5OSC

Q103

FM IF

AMP

AM OSC

T201

D201

TU VCC

CF101,102

10.7MHz

CT201

L201

BAR ANT

Q201

RF

AMP

Q202

T202

AM MIX

Q205

CF202

450kHz

TU VCC

TU VCCTU VCC

Q203

BAND

3

6

4

24

2

22 21 20

18 19

16

S305

MEGA BASS

Q303

ON

OFF

RV301

VOL

Q302(1/2)

Q302(2/2)

TU VCC

27

28

26

29

3

43

42 41

18

AUDIO

POWER AMP

IC301

IN L

IN R

NF L

NF R

REF OUT

BST SW

PW SW MT SW

BASE

OUT L

OUT C

AGC IN

OUT R

J301

22

21 35 20

• RCH is omitted

• Signal Path

: FM

: AM

• Abbreviation JE : Tourist model.

TU VCC

S304

FM

DX LOCAL

VCC

IC402

IF

COUNTER

Q204

LOCAL

JE MODEL

S303 HOLD

/DX

DIGITAL TUNING

SYSTEM CONTROL

IC401

HOLD SW

26

OFFON

53

50

MUTE

AM PON

POWER ON

KR224KR3

KR1

23

25

-1

-2

-3

KS121KS2

22

S401

POWER

S302

MODE

S301

JOG

Q104,105

IC101

+B

T401

Q402,405

DC-DC

CONV

L.P.F Q403

VDD

34

12

35

36

40

DO

INT2

INT1

IF INT2

COM1 COM4

14

38

OSC IN

LCD1

LIQUID CRYSTAL

DISPLAY

S1 S12

516

Q401

31

DDC ON

55

TU VCC

VCC

X OUT

X401

75kHz

52

BAND

X IN

56

TU VCC VCC

28

BEEP

RESET

54

51

Q301

IC403

RESET

VCC

VDD

Q406

DRY BATTRY

SIZE "AAA"

(IEC DESIGNATION R03)

1PC 1.5V

55