Sony MDS-JA50ES / Mode d’emploi User manual

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SPECIFICATIONS
Model Name Using Similar Mechanism NEW
MD Mechanism Type MDM-4A
Base Unit Type MBU-2B
Optical Pick-up Type KMS-210A/J-N
MDS-JA50ES
SERVICE MANUAL
US Model
AEP Model
UK Model
MINIDISC DECK
MICROFILM
Photo: GOLD

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CAUTION
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.
ADVARSEL!
Lithiumbatteri - Eksplosionsfare ved fejlagtig håndtering.
Udskiftning må kun ske med batteri af samme fabrikat og type.
Levér det brugte batteri tilbage til leverandøren.
ADVARSEL
Eksplosjonsfare ved feilakting skifte av batteri.
Benytt samme batteritype eller en tilsvarende type anbefalt av
apparatfabrikanten.
Brukte batterier katterier kasseres i henhold til fabrikantens
VARNIG
Explosionsfara vid felaktigt batteribyte.
Användsammabatteritypellerenlikvärdigtypsomrekommenderas
av apparattillverkaren.
Kassera använt batteri enligt gällande föreakrifter.
VAROITUS
Parist voi räjähtää, jos se on virheellisesti asennettu.
Vaihda paristo ainoastaan laitevalmistajan suosittelemaan tyyppiin.
Hävitä käytetty paristo valmistajan ohjeiden mukaisesti.
To Exposed Metal
Parts on Set
0.15µF 1.5k
Ω
AC
voltmeter
(0.75V)
Earth Ground
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety checks before releasing the set to the customer:
Checktheantennaterminals,metaltrim,“metallized”knobs,screws,
and all other exposed metal parts forAC 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
returnto chassis, must not exceed 0.5 mA (500 microampers). Leak-
age 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 aVOM
or battery-operatedAC 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 pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)
Fig. A. Using an AC voltmeter to check AC leakage.
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.

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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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
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.
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.
The laser component in this product is
capable of emitting radiation exceeding
the limit for Class 1.
MODEL IDENTIFICATION
— BACK PANEL —
Parts No.
4-987-511-2 : AEP, UK, German model
4-987-511-3 : US model
TABLE OF CONTENTS
1. SERVICING NOTE .......................................................... 4
2. GENERAL .......................................................................... 7
3. DISASSEMBLY
3-1. Tray Assembly .................................................................... 26
3-2. Bracket (Motor) ASSY ....................................................... 27
3-3. Holder ASSY ...................................................................... 27
3-4. Base Unit............................................................................. 28
3-5. HMOT Board and HLIM Board ......................................... 28
4.TEST MODE ..................................................................... 29
5. ELECTRICAL ADJUSTMENTS ............................... 32
6. DIAGRAMS
6-1. Brock Diagrams
• BD Section ....................................................................... 37
• Digital Section ................................................................. 39
• Audio Section .................................................................. 41
• Power Section .................................................................. 43
6-2. Circuit Boards Location ...................................................... 44
6-3. Waveforms ......................................................................... 45
6-4. Printed Wiring Board — BD Section —............................. 47
6-5. Schematic Diagram — BD Section — ............................... 49
6-6. Schematic Diagram — Digital Section —.......................... 52
6-7. Printed Wiring Board — Digital Section — ....................... 55
6-8. Printed Wiring Board — MD Section —............................ 57
6-9. Schematic Diagram — MD Section — .............................. 58
6-10. Printed Wiring Board — D Out, D Vol Section — .......... 59
6-11. Schematic Diagram — D Out, D Vol Section — ............. 60
6-12. Printed Wiring Board — DA Section —.......................... 61
6-13. Schematic Diagram — DA Section —............................. 63
6-14. Printed Wiring Board — AD Section — .......................... 65
6-15. Schematic Diagram — AD Section — ............................. 67
6-16. Printed Wiring Board — Panel Section —....................... 69
6-17. Schematic Diagram — Panal Section — ......................... 71
6-18. Printed Wiring Board — Power Section — ..................... 73
6-19. Schematic Diagram — Power Section — ........................ 75
6-20. IC Block Diagrams ........................................................... 77
6-21. IC Pin Functions ............................................................... 84
7. EXPLODED VIEWS
7-1. Main Section ..................................................................... 100
7-2. Chassis Section ................................................................. 101
7-3. Front Panel Section 1 ........................................................102
7-4. Front Panel Section 2 ........................................................103
7-5. Mechanism Section 1 (MDM-4A) ....................................104
7-6. Mechanism Section 2 (MDM-4A) ....................................105
7-7. Mechanism Section 3 (MDM-4A) ....................................106
7-8. Base Unit Section (MBU-2B) ........................................... 107
8. ELECTRICAL PARTS LIST ...................................... 108

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SECTION 1
SERVICING NOTE
HOWTO OPENTHE DISCTRAY WHEN POWER SWITCH TURNS OFF
1Remove the fourteen screws (BVTT 3x8) from the bottom plate.
2Remove the bottom plate.
3Rotate the pulley gear in the arrow direction A, and open the tray assembly in the arrow direction B.
Pully gear
A
B
Tray assembly
FORCED RESET
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:
Disconnectthepower plug, and short-circuit CN905 of the PWboard
with a pair of tweezers, etc.
[PW board] (Component Side)
CN905
(RESET)
CN901
Method 1:
Set TP (S.RST) of the DIG board to ground momentarily.
[DIG board] (Side A)
TP
(S.RST)
CN203
C206
IC202

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RETRY CAUSE DISPLAY MODE
• In this test mode, the causes for retry of the unit during recording can be displayed on the fluorescent display tube.
This is useful for locating the faulty part of the unit.
• The retry cause, number of retries, and number of retry errors are displayed. Each is displayed in hexadecimal number.
Method:
1. Load a recordable disc whose contents can be erased into the unit.
2. Press the pbutton, §OPEN/CLOSE button, DISPLAY/CHAR button simultaneously.
3. Press the rbutton, and start recording.
4. The ## value increases with each retry. If an error occurs after a retry, the @@ count will also increase.
5. To exit the test mode, press the TIME button.
Fig. 1 Reading theTest Mode Display
R.T s ∗∗c # # e @@
Fluorescent DisplayTube Signs
∗∗: Cause of retry
# # : Number of retries
@@: Number of retry errors
All three displays above are in hexadecimal numbers.

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Reading the Retry Cause Display
Hexadecimal
Bit
Binary
Higher Bits Lower Bits
84218421
b7 b6 b5 b4 b3 b2 b1 b0
00000001
00000010
00000100
00001000
00010000
00100000
01000000
10000000
When more than 3.5 shocks are detected
When ADER was counted more than
five times continuously
When ADIP address is not continuous
(Not used)
When not in focus
When ABCD signal level exceeds the specified range
When spindle rotation is detected as slow
When access operation is not performed normally
Hexa-
decimal
shock *1
ader5
Discontinuousaddress
(Not used)
FCS incorrect
IVR rec error
Spindle is slow
Access fault
Cause of Retry Occurring conditions
01
02
04
08
10
20
40
80
*1 Some displays are not used depending on the microprocessor version.
Reading the Display:
Convert the hexadecimal display into binary display. If more than two causes, they will be added.
Example
When 42 is displayed:
Higher bit : 4 = 0100 nb6
Lower bit : 2 = 0010 nb1
In this case, the retry cause is combined of “spindle is slow” and “ader5”.
When A2 is displayed:
Higher bit : A = 1010 nb7+b5
Lower bit : 2 = 0010 nb1
The retry cause in this case is combined of “access fault”, “IVR rec error”, and “ader5”.
Hexadecimal n Binary ConversionTable
Hexadecimal Binary Hexadecimal Binary
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Reference:
In this test mode, when the ·button is pressed, and the disc is played back, the “PLAYBACK MODE” is set.
The display becomes as shown in Fig. 2. The playback mode is not used in particular during servicing.
44 ¢¢¢¢¢¢ p
Fig. 2 Display during Playback Mode
4: Parts No. (Name of area named on TOC)
¢¢¢¢¢¢ : Address (Physical address on disc)
p: Track mode (Copyright information of each part, information on copyright, etc.)

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SECTION 2
GENERAL
Location of Parts and Controls
1POWER switch
2Remote sensor
3TIMER switch
4FILTER button
5SCROLL/CLOCK SET button
6DISPLAY/CHAR button
7Disc tray
80/) (fast backward/fast forward) buttons
9EDIT/NO /YES buttons
Pressing the EDIT/NO button once, it becomes the edit menu
and the recorded disc can be programmed.
Pressing it twice it becomes the set up menu (page 43), and
various settings are possible.
!º AMS knob
!¡ DIGITAL REC LEVEL knob
!™ ANALOG REC LEVEL L/R knob
!£ rREC (recording) button
!¢ p(stop) button
!∞ P(pause) button
!§ ((play) button
!¶ §OPEN/CLOSE button
!• Display window
!ª TIME button
@º REPEAT button
@¡ PLAY MODE button
@™ INPUT switch
@£ PHONE LEVEL knob
@¢ PHONES jack
12 34567 890!¡ !™
!£!¢
!∞
!§
!¶
!•!ª
@º
@¡
@™
@£
@¢

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This section is extracted from
instruction manual.

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