SAFETY CHECK-OUT

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.

LEAKAGE

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)

To Exposed Metal

Parts on Set

 

 

 

 

 

 

 

 

AC

 

 

 

 

 

 

 

 

0.15 F

 

 

 

 

Ω

 

 

Voltmeter

 

 

 

 

 

 

1.5 k

 

 

(0.75 V)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Earth Ground

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

MODEL IDENTIFICATION

— BACK PANEL —

Parts No.

TABLE OF CONTENTS

 

1. SERVICING NOTE

5

2. GENERAL

8

3. DISASSEMBLY

 

3-1. Case and Front Panel Assembly

9

3-2. Bracket (T), (L) and (R)

9

3-3. BD Board

10

3-4. SUB Chassis

10

3-5. Shutter Assembly

11

3-6. Over Write Head

11

3-7. Slider Complete Assembly

12

4. TEST MODE

13

5. ELECTRICAL ADJUSTMENTS

16

6. DIAGRAMS

 

6-1. Brock Diagrams

 

• BD Section

21

• Main Section

23

6-2. Circuit Boards Location

25

6-3. Printed Wiring Board — BD Section

27

6-4. Schematic Diagram — BD Section (1/2)

29

6-5. Schematic Diagram — BD Section (2/2)

31

6-6. Printed Wiring Board — Main Section

33

6-7. Schematic Diagram — Main Section (1/3)

35

6-8. Schematic Diagram — Main Section (2/3)

37

6-9. Schematic Diagram — Main Section (3/3)

39

6-10. Printed Wiring Board — Display Section

41

6-11. Schematic Diagram — Display Section

43

6-12. Printed Wiring Board — Switch Section

45

6-13. Schematic Diagram — Switch Section

47

6-14. IC Brock Diagrams — BD Section—

49

6-15. IC Pin Functions

54

7. EXPLODED VIEWS

 

7-1. Main Section

63

7-2. Front Panel Section

64

7-3. Mechanism Deck Section (1) (MDM-3GC)

65

7-4. Mechanism Deck Section (2) (MDM-3GC)

66

8. ELECTRICAL PARTS LIST

67

Parts No.

Model

 

 

4-990-651-1

US model

 

 

4-990-651-4

Canadian model

 

 

4-990-651-5

AEP model

 

 

— 3 —

Page 3
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Sony MDS-JD320 service manual Table of Contents, Disassembly, Diagrams, Exploded Views

MDS-JD320 specifications

The Sony MDS-JD320 is a MiniDisc recorder that exemplifies the cutting-edge technology of the late 1990s and early 2000s. Designed for both amateur and professional audiophiles, it delivers superior sound quality and an array of features that enhance user experience and functionality. Key to its appeal is its remarkable sound reproduction capabilities, which are achieved through Sony's proprietary technologies, including the ATRAC (Adaptive Transform Acoustic Coding) compression format. This format allows for efficient audio storage without sacrificing sound fidelity, ensuring that each recording is as rich and dynamic as the original source.

One of the standout features of the MDS-JD320 is its ability to create, edit, and playback CDs and MiniDiscs with remarkable ease. Thanks to its digital optical input and output, users can connect the device to various audio sources, such as CD players or mixing boards, to make high-quality recordings. The device supports various recording modes, including long play, which enables users to extend their recording time without significant compromise on audio quality.

The MDS-JD320 also boasts a user-friendly interface, which includes an LCD display that conveniently shows essential information such as track numbers, remaining time, and recording mode. Furthermore, an intuitive remote control offers added convenience, allowing users to navigate through their music collections without having to physically interact with the device.

In terms of connectivity, the MDS-JD320 features not only digital inputs and outputs but also analog connections, making it versatile for various setups. Additionally, the device includes extensive editing features, such as track splitting, combining, and renaming, empowering users to customize their recordings easily.

Moreover, the MDS-JD320's compact design fits seamlessly into any audio setup, making it an attractive choice for both home recording enthusiasts and professionals. Its durable build quality ensures longevity, while its performance continues to impress even in today's digital audio landscape.

With its powerful combination of advanced technologies, ease of use, and high-quality audio performance, the Sony MDS-JD320 remains a sought-after component for collectors and audiophiles alike, representing an enduring legacy in the field of portable digital media solutions.