Sony ST-EX880, SТ-MS717 Service Manual

ST-EX880/MS717

SERVICE MANUAL

AEP Model

UK Model

ST-EX880

E Model

Tourist Model

ST-MS717

ST-EX880/MS717 are the tuner section	Photo: ST-MS717
in DHC-EX880MD/MD717.

SPECIFICATIONS

FM STEREO/FM-AM TIMER TUNER

MICROFILM

	TABLE OF CONTENTS
1.	SERVICING NOTES ...............................................	2
2.	GENERAL ...................................................................	3
3.	DISASSEMBLY .........................................................	5
4.	ELECTRICAL ADJUSTMENTS .........................	6

5.DIAGRAMS

5-1. Note for Printed Wiring Boards and
	Scehmatic Diagrams .......................................................	7
5-2. Printed Wiring Board – MAIN Section –
	(ST-EX880) .....................................................................	9
5-3. Printed Wiring Board – MAIN Section –
	(ST-MS717) .....................................................................	11
5-4.	Schematic Diagram – MAIN Section (1/2) – .................	13
5-5.	Schematic Diagram – MAIN Section (2/2) – .................	15
5-6.	Printed Wiring Board – PANEL Section – .....................	17
5-7.	Schematic Diagram – PANEL Section – ........................	19
5-8. Schematic Diagram – RDS Section – (ST-EX880) ........		21
5-9. Printed Wiring Board – RDS Section – (ST-EX880) .....		21
5-10. Schematic Diagram – POWER Section – ......................		22
5-11. Printed Wiring Boards – POWER Section – ..................		23
5-12. IC Pin Function Description ...........................................		25
6.	EXPLODED VIEWS ................................................	29
7.	ELECTRICAL PARTS LIST ...............................	31

MODEL IDENTIFICATION

– Back Panel –

4-995-091-1 : Hong Kong, Singapore, Malaysia

4-995-091-2 : AEP, UK

4-995-091-3 : Tourist

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.

SECTION 1

SERVICING NOTES

KEYs FLUORESCENT INDICATOR TUBE/LEDs CHECK MODE (Work a separately)

1.Press [POWER] button.

2.Press two buttons [POWER] and [SLEEP] simultaneously.

3.LEDs are all turned on, the fluorescent indicator tube displays

“KEY/FL/LED”, and the check mode is set. 1 All LED indicators light on mode

↓

2 All Fluorescent indicator tube light on mode

↓

3 ST segment mode

↓

4 RDS segment mode

↓

5 Encoder and key check mode

Note:

1)All LED light on mode is kept, when buttons which is pressed to enter all LED light on mode, release same time.

When release them separate timing, it is moved to next All Fluorescent indicator tube light on mode.

2)After all LED light on mode, light on point remove one by one, when any button pressed or [MULTI CONTROLLER] knob turned.

3)Under KEY check mode, every time buttons pressed numerical value of “KEY=” in FL tube increase.

And that time, numerical value of “ECDR=” increase when [MULTI CONTROLLER] button turn to + direction, and it decrease

turn to – direction.

To exit from this mode, disconnect the power cord.

TUNER CHECK MODE (Work a separately)

1.Press [POWER] button.

2.Press two buttons [POWER] and [ENTER/YES] simultaneously, and the tuner check mode is set.

3.System power on, set up the tuner function, and test condition

inactive.

Press two buttons [POWER] and [ENTER/YES] simultaneously to exit, and system power off.

COLD RESET (Work a complex)

The cold reset clears each unit microcomputer memory to initial conditions.

1.Press [POWER] button to turn the set OFF.

2.Press three buttons [MENU/NO], [PRESET], and [POWER] simultaneously.

3.A message “COLD SET OK” is displayed on the fluorescent indicator tube two seconds.

4.Press [POWER] button to turn the set OFF.

5.Remove power cord after the clock is displayed on the fluorescent indicator tube.

6.Connect power cord, press [POWER] button to turn the set ON, and the set is reset.

– 2 –

SECTION 2

GENERAL

LOCATION OF CONTROLS

– Front Panel –

– Rear Panel –

This section is extracted from instruction manual.

1 I/u(POWER) button

2 REMOTE CONTROL receiver

3 ONCE, DAILY, REC, SLEEP indicator

4 REC button

5 DAILY button

6 ONCE button

7 CLOCK/TIMER SET button

8 STEREO/MONO button

9 SLEEP button

!º MULTI CONTROLLER knob

!¡ ENTER/YES button

!™ MENU/NO button

!£ BAND button

!¢ RESET button

! Fluorescent indicator tube

!§AUTO/nbutton

!¶ MANUAL/Nbutton

!• DISPLAY button

!ª TUNER OUT terminal

@º FM/AM ANTENNA terminal

@¡AU BUS terminal

@™ SYSTEM CONTROL terminal

@£AC OUTLET (for TA-MS717)

@¢ POWER cord

– 3 –

– 4 –

SECTION 3

DISASSEMBLY

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

MAIN BOARD

1 two screws

(case3 TP2)

3 case

2 screw

(BVTT3 × 6)

1 two screws

(case3 TP2)

5 connector (CN104)

9 two screws

4 flat type wire (19 core) (BVTP3 × 8) (CN102)

!™ MAIN board

!¡ claw

8 front panel ass’y

7 claw	0 three screws
	(BVTP3 × 10)

!¡ claw

7 two claws

6two screws (BVTT3 × 6)

– 5 –

SECTION 4

ELECTRICAL ADJUSTMENTS

0 dB=1 µV

Note: As a front-end (FE1) is difficult to repair if faulty, replace it with new one.

AM Section Adjustment

Setting:

loop antenna	loop antenna
	(Supplied accessories)

AM RF SSG
30% amplitude
modulation by							60 cm
400 Hz signal
Carrier frequency : 999 kHz (at 9 k step)
Output level				1,000 kHz (at 10 k step)
			: 25 dB

set

AM ANTENNA terminal

Field strength dB (V/m) =SSG output level dB (V/m) –26 dB.

AM Tuned Level Adjustment

Band: AM or MW

Procedure:

1.Set the output of SSG so that the input level of the set becomes 55 dBµ/m.

2.Tune the set to 999 kHz or 1,000 kHz.

3.Adjust RV1 to the point (moment) when the TUNED indicator will change from going off to going on.

Adjustment Location : MAIN board

FM Section Adjustment

Note: This adjustment should be performed after the AM Tuned Level Adjustment due to the same adjustment element.

Setting:

FM RF stereo signal generator

				75 Ω coaxial
							set
Carrier frequency : 98 MHz
Modulation	: AUDIO 1 kH, 75 kHz				FM ANTENNA terminal
		deviation (100%)
Output level	: 26 dB (17.8 V)				(75 Ω open)

FM Tuned Level Adjustment

Band: FM

Procedure:

1.Supply a 26 dBµ 98 MHz signal from the ANTENNA terminal.

2.Tune the set to 98 MHz.

3.If the TUNED indicator does not light, adjust RV2 to the point

(moment) when the TUNED indicator will change from going off to going on.

Adjustment Location: MAIN board

Adjustment Location:

[MAIN BOARD] (Component Side)

RV1

IC1

FE1

RV2

– 6 –

SECTION 5

DIAGRAMS

5-1. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS

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 W and 1/4 W or less unless otherwise specified.

•¢ : internal component.

•2 : nonflammable 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 and waveforms are dc with respect to ground

under no-signal (detuned) conditions. no mark : FM

(	) : AM (MW)
áá	ññ : STAND BY
[	] : MUTING ON

•Voltages are taken with a VOM (Input impedance 10 MW). 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 : FM

f : AM (MW)

•Circuit Boards Location

Note on Printed Wiring Boards:

•X : parts extracted from the component side.

•¢ : internal component.

•Indication of transistor.

Q

B C E

These are omitted.

Abbreviation:

HK	: Hong Kong
JE	: Tourist
MY	: Malaysia
SP	: Singapore

AC OUTLET board (Tourist model)

TRANSFORMER board

MAIN board

PANEL board

RDS board

(ST-EX880)

ST-EX880/MS717

• Waveforms	– PANEL Section –
– MAIN Section –
1 IC51 1 (XIN)	4 IC901 @º (XOUT)

2.9Vp-p	5.2Vp-p

4.5 MHz	513 kHz
2 IC201 $¡ (X2)	5 IC901 @¡ (XIN)

4.4Vp-p

880 mVp-p

10 MHz

504 kHz

3 IC201 $¢ (XT2)

4.8Vp-p

32.768 kHz

– 7 –

– 8 –

ST-EX880/MS717

5-2. PRINTED WIRING BOARD – MAIN Section – (ST-EX880)

•See page 7 for Circuit Boards Location.

•Semiconductor Location

Ref. No.	Location
D1	F-1
D2	E-2
D103	G-7
D104	E-7
D105	E-6
D125	B-5
D143	D-6
D161	D-7
D191	D-2
D272	G-8
D281	H-4
D282	G-4
IC1	E-4
IC51	C-2
IC111	C-7
IC171	I-6
IC201	G-6
Q1	C-4
Q2	C-4
Q9	C-4
Q10	C-5
Q11	A-3
Q12	A-4
Q13	A-4
Q14	B-4
Q15	B-4
Q55	E-2
Q121	B-5
Q122	B-5
Q123	C-5
Q141	D-6
Q142	D-6
Q201	F-6
Q202	B-6
Q203	B-7
Q273	G-8
Q274	G-8
Q281	H-4

(Page 21)

(Page 24)

(Page 20)

– 9 –

– 10 –