MDS-JA30ES - Sony Audio Service Manual (repair manual)

US Model

Canadian Model

AEP Model

UK Model

MICROFILM

Model Name Using Similar Mechanism

MDS-JA50ES

MD Mechanism Type

MDM-4B

Base Unit Type

MBU-2B

Optical Pick-up Type

KMS-210A/J-N

— Continued on next page —

U.S. and foreign patents licensed from Dolby Laboratories
Licensing Corporation.

Photo: GOLD

— 2 —

!

!

!

    After correcting the original service problem, perform the
following safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.

    The AC leakage from any exposed metal part to earth ground
and from all exposed metal parts to any exposed metal part having
a return to chassis, must not exceed 0.5 mA (500 microampers).
Leakage current can be measured by any one of three methods.

1.

A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instruments.

2.

A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.

3.

Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC voltmeter. The “limit” indication
is 0.75 V, so analog meters must have an accurate low-voltage
scale. The Simpson 250 and Sanwa SH-63Trd are examples of
a passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2V AC range are suitable. (See
Fig. A)

Danger of explosion if battery is incorrectly replaced.
Replace only with the same or equivalent type recommended by
the equipment manufacturer.
Discard used batteries according to manufacture’s instructions.

Lithiumbatteri - Eksplosionsfare ved fejlagtig håndtering.

Udskiftning må kun ske med batteri af samme fabrikat og type.

Levér det brugte batteri tilbage til leverandøren.

Eksplosjonsfare ved feilakting skifte av batteri.

Benytt samme batteritype eller en tilsvarende type anbefalt av

apparatfabrikanten.

Brukte batterier katterier kasseres i henhold til fabrikantens

Explosionsfara vid felaktigt batteribyte.
Använd samma batterityp eller en likvärdig typ som rekommenderas
av apparattillverkaren.
Kassera använt batteri enligt gällande föreakrifter.

Parist voi räjähtää, jos se on virheellisesti asennettu.
Vaihda paristo ainoastaan laitevalmistajan suosittelemaan tyyppiin.
Hävitä käytetty paristo valmistajan ohjeiden mukaisesti.

Earth Ground

AC
voltmeter
(0.75V)

1.5k

Ω

0.15

µ

F

Fig. A.  Using an AC voltmeter to check AC leakage.

To Exposed Metal 
Parts on Set

— 3 —

This appliance is classified as a CLASS 1
LASER product. The CLASS 1 LASER
PRODUCT MARKING is located on the
rear exterior.

The following caution label is located
inside the unit.

Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous
radiation exposure.

• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be

damaged by heat.

• 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.

The laser component in this product is
capable of emitting radiation exceeding
the limit for Class 1.

Parts No.

4-992-959-1

 : AEP, UK, German model

4-992-959-2

 : US model

4-992-959-3

 : Canadian model

······················································ 4

······································································ 7

3-1.

Tray Assembly ···································································· 8

3-2.

Bracket (Motor) ASSY ······················································· 9

3-3.

Holder ASSY ······································································ 9

3-4.

Base Unit ·········································································· 10

3-5.

HMOT Board and HLIM Board ······································· 10

································································ 11

··························· 14

6-1.

BD Section ······································································· 19

6-2.

Digital Section ·································································· 21

6-3.

Audio Section ··································································· 23

6-4.

Power Section ··································································· 25

6-5.

Circuit Boards Location ··················································· 26

6-6.

Printed Wiring Board — BD Section — ·························· 28

6-7.

Schematic Diagram — BD Section — ····························· 31

6-8.

Schematic Diagram — Digital Section — ······················· 35

6-9.

Printed Wiring Board — Digital Section — ···················· 39

6-10. Printed Wiring Board — Audio Section — ······················ 42
6-11. Schematic Diagram — Audio Section — ························· 45
6-12. Schematic Diagram — Power Section — ························ 48
6-13. Schematic Diagram — Panel Section — ························· 51
6-14. Printed Wiring Board — Panel Section — ······················· 53
6-15. IC Block Diagrams ··························································· 56
6-16. IC Pin Functions ······························································· 61

7-1.

Main Section ····································································· 73

7-2.

Chassis Section ································································· 74

7-3.

Front Panel Section 1 ······················································· 75

7-4.

Front Panel Section 2 ······················································· 76

7-5.

Mechanism Section 1 (MDM-4B) ···································· 77

7-6.

Mechanism Section 2 (MDM-4B) ···································· 78

7-7.

Mechanism Section 3 (MDM-4B) ···································· 79

7-8.

Base Unit Section (MBU-2B) ·········································· 80

··································· 81

— 4 —

1 Remove the sixteen screws (BVTT 3

×

8) from the bottom plate.

2 Remove the bottom plate.
3 Rotate the pulley gear in the arrow direction A, and open the tray assembly in the arrow direction B.

The system microprocessor can be reset in the following way.
Use these methods when the unit cannot be operated normally due to the overrunning of the microprocessor, etc.

Method 2:
Disconnect the power plug, and short-circuit CN905 of the PW board
with a pair of tweezers, etc.

CN905
(RESET)

CN901

Method 1:
Set TP (S.RST) of the DIG board to ground momentarily.

TP

(S.RST)

CN203

C206

IC202

Pully gear

Tray assembly

B

A