Sony MDSJB-940 Service manual

MDS-JB940

SERVICE MANUAL

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

SPECIFICATIONS

System Disc Laser

Laser output

Laser diode Revolutions (CLV) Error correction

Sampling frequency Coding

Modulation system

Number of channels Frequency response Signal-to-noise ratio Wow and flutter

Inputs

ANALOG IN

MiniDisc digital audio system MiniDisc Semiconductor laser (λ = 780 nm)

Emission duration: continuous MAX 44.6 µW

1) This output is the value

Material: GaAlAs 400 rpm to 900 rpm ACIRC (Advanced Cross Interleave

Reed Solomon Code)

44.1 kHz ATRAC (Adaptive TRansform

Acoustic Coding)/ATRAC 3 EFM (Eight-to-Fourteen

Modulation) 2 stereo channels 5 to 20,000 Hz ±0.3 dB Over 100 dB during pla y Below measurable limit

Jack type: phono Impedance: 47 kilohms Rated input: 500 mVrms Minimum input: 125 mVrms

measured at a distance of 200 mm from the objective lens surface on the Opt ical Pick-up Block with 7 mm aperture.

DIGITAL OPTICAL IN1

DIGITAL OPTICAL IN2

DIGITAL COAXIAL IN

Outputs

PHONES

ANALOG OUT

DIGITAL OPTICAL OUT

DIGITAL COAXIAL OUT

Connector type: square optical Impedance: 660 nm (optical wave length)

Jack type: phono Impedance: 75 ohms Rated input: 0.5 Vp-p, ±20 %

Jack type: stereo phone Rated output: 28 mW Load impedance: 32 ohms

Jack type: phono Rated output: 2 Vrms (at 50 kilohms) Load impedance: over 10 kilohms

Connector type: square optical Rated output: –18 dBm Load impedance: 660 nm (opti cal wave length)

Jack type: phono Rated output: 0.5 Vp-p (at 75 ohms) Load impedance: 75 ohm s

US Model

Canadian Model

AEP Model

UK Model

Model Name Using Similar Mechanism NEW MD Mechanism Type MDM-7A Optical Pick-up Name KMS-260B/J1N

General

Power requirements

Where purchased Power requirements

U.S.A. and Canada 120 V AC, 60 Hz Europe 230 V AC, 50/60 Hz

Power consumption Dimensions (approx. )

Mass (approx.)

Supplied accessories

This MD deck comes with the following items:

Audio connecting cords (2) Optical cable (1) Remote commander (remote) (1) R6 (size-AA) batteries (2)

US and foreign patents licensed from Dolby Labora t ories. Design and specifications are subject to change without

notice.

18 W 430 × 111 × 286 mm (17 × 4

/8 in.) (w/h/d) incl. projecting

11 parts and controls

5.3 kg (11 lbs 11 oz)

/8 ×

MINIDISC DECK

SAFETY CHECK-OUT

SELF-DIAGNOSIS FUNCTION ········································ 4

1. SERVICE NOTE ······························································· 6

2. GENERAL ········································································ 11

3. DISASSEMBLY ······························································ 14

4. TEST MODE··································································· 17

5. ELECTRICAL ADJUSTMENTS······························ 22

6. DIAGRAMS

6-1. Block Diagram MAIN Section································ 31 6-2. Block Diagram DISPLAY/POWER Section ··········· 32 6-3. Note for Printed Wiring Boards and

Schematic Diagrams···················································· 33 6-4. Circuit Board Location ················································ 33 6-5. Waveforms··································································· 34 6-6. Printed Wiring Board BD Board ····························· 35 6-7. Schematic Diagram BD Board (1/2) ······················· 36 6-8. Schematic Diagram BD Board (2/2) ······················· 37 6-9. Printed Wiring Board HP Board/KEY Board·········· 38 6-10.Schematic Diagram HP Board/KEY Board ············ 38 6-11.Schematic Diagram MAIN Board (1/3) ·················· 39 6-12.Schematic Diagram MAIN Board (2/3) ·················· 40 6-13.Schematic Diagram MAIN Board (3/3) ·················· 41 6-14.Printed Wiring Board MAIN Board (Side A) ·········· 42 6-15.Printed Wiring Board MAIN Board (Side B)·········· 43 6-16.Printed Wiring Board PANEL Section ···················· 44 6-17.Schematic Diagram PANEL Section······················· 45 6-18.Schematic Diagram AC Board ································ 46 6-19.Printed Wiring Board AC Board······························ 47 6-20.IC Block Diagrams ······················································ 48 6-21.IC Pin Function Description ········································ 53

7. EXPLODED VIEWS ······················································ 60

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 A C leakage. Check leakage as described below.

LEAKAGE

The A C leakag e from any exposed metal part to earth g round and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes). 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. Follo w 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 A C voltmeter . The “limit” indication is 0.75 V, so analog meters must have an accurate low-v oltage scale. The Simpson 250 and Sanwa SH-63Trd are e xamples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2V AC range are suitable. (See Fig. A)

T o Exposed Metal

Parts on Set

0.15 µF

1.5 kΩ

Voltmeter (0.75 V)

8. ELECTRICAL PARTS LIST ······································· 64

Earth Ground

Fig. A. Using an A C v oltmeter to check A C leakage.

MODEL IDENTIFICATION

— BACK PANEL —

Model

AEP, UK models Canadian model US model

4-228-507-0s 4-228-507-1s 4-228-507-2s

Part No.

CAUTION

Danger of explosion if battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacturer. Discard used batteries according to the manufacturer’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 feilaktig skifte av batteri.

Benytt samme batteritype eller en tilsvarende type

anbefalt av apparatfabrikanten.

Brukte batterier kasseres i henhold til fabrikantens

instruksjoner.

VARNING

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

VAROITUS

Paristo voi räjähtää, jos se on virheellisesti asennettu. V aihda paristo ainoastaan laitev almistajan suosittelemaan tyyppiin. Hävitä käytetty paristo valmistajan ohjeiden mukaisesti.

NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK OR BASE UNIT

The laser diode in the optical pick-up block may suffer electrostatic break-down because of the potential difference generated by the charged electrostatic load, etc. on clothing and the human body. During repair, pay attention to electrostatic break-down and also use the procedure in the printed matter which is included in the repair parts. The flexible board is easily damaged and should be handled with care.

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

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 radiation exposure.

Notes on chip component replacement

• Nev er 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.

NOTES ON LASER DIODE EMISSION CHECK

The laser beam on this model is concentrated so as to be focused on the disc reflective surface by the objective lens in the optical pickup block. Therefore, when checking the laser diode emission, observe from more than 30 cm away from the objective lens.

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 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 .

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ! LES COMPOSANTS IDENTIFÉS P AR UNE MARQUE 0 SUR LES DIAGRAMMES SCHÉMA TIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.

SELF-DIAGNOSIS FUNCTION

The self-diagnosis function consists of error codes for customers which are displayed automatically when errors occur, and error codes whic h show the error history in the test mode during servicing. For details on how to view error codes for the customer, r efer to the following box in the instruction manual. For details on how to check error codes during servicing, refer to the following “Procedure for using the Self- Diagnosis Function (Error History Display Mode)”.

The deck’s self-diagnosis function automatically checks the condition of the MD dec k when an error occurs, then issues a three- or fi ve-digit code and an error message on the display. If the code and message alternate, find them in the following table and perform the indicated countermeasure. Should the problem persist, consult your nearest Sony dealer.

Three- or fivedigit code/ Message

C11/Protected

C12/Cannot Copy

C13/REC Error

C13/Read Error

C14/To c Error

C41/Cannot Copy

Cause/Remedy

The inserted MD is record-protected.

Take out the MD and close the recordprotect slot (page 15).

You tried to record a CD with a format that the external device connected t o the deck does not support, such as CD-ROM or video CD.

Remove the disc and insert a music CD.

The recording was not made properly.

Set the deck in a stable surface, and repeat the recording procedure.

The inserted MD is dirty (with smudges, fingerprints, etc.), scratched, or substandard in quality.

Replace the disc and repeat the recording procedure.

The deck could not read the TOC on the MD properly.

Take out the MD and insert it again.

The deck could not read the TOC on the MD properly.

Insert another disc. If possible, erase all the tracks on the MD (page 32).

The sound source is a copy of commercially available music software, or you tried to record a CD-R (Recordable CD).

The Serial Copy Management System prevents making a digital copy (page 52). Yo u cannot record a CD-R.

Three- or fivedigit code/ Message

C71/Din Unlock

E0001/ MEMORY NG

E0101/ LASER NG

Cause/Remedy

The sporadic appearance of this message is caused by the digital signal being recorded. This will not affect the recording.

While recording from a dig ital c ompon ent connected through the DIGIT AL IN connector, the digital connecti ng cable was unplugged or the digital compon e nt turned off.

Connect the cable or turn the digital component back on .

There is an error in the internal data that the deck needs in order to operate.

Consult your nearest Sony dealer.

There is a problem with the optical pickup.

The optical pickup may have failed. Consult your nearest Sony dealer.

PROCEDURE FOR USING THE SELF-DIAGNOSIS FUNCTION (ERROR HISTORY DISPLAY MODE)

Note: Perform the self-diagnosis function in the “error history display mode” in the test mode. The following describes the least required procedure. Be

careful not to enter other modes by mistake. If you set other modes accidentally, press the MENU/NO button to exit the mode.

1. While pressing the l AMS L knob and x button, connect the power plug to the outlet, and release the l AMS L knob and x button. When the test mode is set “[Check]” is displayed.

2. Turn the l AMS L knob and when “[Service]” is displayed, press the YES button.

3. Turn the l AMS L knob to display “Err Display”.

4. Press the YES button to sets the error history mode and displays “op rec tm”.

5. Select the contents to be displayed or executed using the l AMS L knob.

6. Press the l AMS L knob to display or execute the contents selected.

7. Press the l AMS L knob another time to return to step 4.

8. Press the MENU/NO button to display “Err Display” and release the error history mode.

9. To release the test mode, press the REPEAT button. The unit sets into the STANDBY state and the test mode ends.

[ITEMS OF ERROR HISTORY MODE ITEMS AND CONTENTS]

Display

op rec tm

op play tm

spdl rp tm

retry err

total err

err history

retry adrs

er refresh

op change

spdl change

Details of History

Displays the total recording time.

When the total recording time is one minute or longer, displays the time and minute. When the total recording time is less than one minute, displays “Under 1 min”.

The displayed time is about 1/4 of the actual recording time when the laser is set to the high power state. Displays the total playback time.

When the total playback time is one minute or longer, displays the time and minute. When the total playback time is less than one minute, displays “Under 1 min”.

Displays the total time when the spindle motor rotates.

When the total rotation time is one minute or longer, displays the time and minute. When the total rotation time is less than one minute, displays “Under 1 min”.

Displays the total number of retries during recording and number of retry errors during playback. Displayed as “r xx p yy”. “xx” indicates the number of retries during recording, “yy” indicates the number of retry errors during playback. The numbers are displayed in hexadecimal from 00 to FF.

Displays the total number of errors. Displayed as “total xx”. The number is displayed in hexadecimal from 00 to FF.

Displays the last ten errors. Displayed as “0x ErrCd@@”. “x” indicates the history number. A smaller number indicates a more recent error (00 is the latest). @@ indicates the error code. The error history number is selected by turning the l AMS L knob.

Displays the last five retry addresses. Displayed as “xx ADRS yyyy”. “xx” indicates the history number. “yyyy” indicates the cluster where the retry occurred. The history number is selected by turning the l AMS L knob.

Mode which erases the error history and the retry address history

[Operation procedure]

1 When “er refresh” is displayed, press the l AMS L knob. 2 After the display changes to “er refresh?”, press the YES button.

The “Complete!” message indicates that the operation has ended.

After executing this mode, be sure to check the following:

• The data has been erased.

• The mechanism runs normally when recording and playback are performed.

Mode which erases the total time of “op rec tm” and “op play tm” These histories are used as a guideline for the time to replace the optical pick-up. After replacing the optical pick-up, perform this operation to erase the history.

[Operation procedure]

1 When “op change” is displayed, press the l AMS L knob. 2 After the display changes to “op change?”, press the YES button.

The “Complete!” message indicates that the operation has ended.

Mode which erases the total time of “spdl rp tm” The history is used as a guideline for the time to replace the spindle motor. After replacing the spindle motor, perform this operation to erase the history.

[Operation procedure]

1 When “spdl change” is displayed, press the l AMS L knob. 2 After the display changes to “spdl change?”, press the YES button.

The “Complete!” message indicates that the operation has ended.

Table of Error Codes

Error Code

10 12 20 21 22 23 24 30

Loading error The combination of loading switches is not acceptable. Time out. The beginning of PTOC cannot be read. Contents error. The beginning of PTOC can be read. Time out. Access to UTOC failed. Time out. UTOC cannot be read. Contents error of UTOC Playback start error

Details of Error

Error Code

31 40 41 42 43 50

Details of Error

There is an abnormality in the sector contents. An error caused a retry during continuous recording. Retry was executed due to DRAM overflow. Retry was executed during TOC writing. S.F Edit was aborted due to retry. Address cannot be read although access processing is not in progress. Runaway due to focus NG

SECTION 1

SERVICE NOTE

JIG FOR CHECKING BD BOARD WAVEFORM

The special jig (J-2501-196-A) is useful for checking the waveform of the BD board. The names of terminals and the checking items to be performed are shown as follows.

GND : Ground I+3V : For measuring IOP (Check the deterioration of the optical pick-up laser) IOP : For measuring IOP (Check the deterioration of the optical pick-up laser) TEO : TRK error signal (Traverse adjustment) VC : Reference level for checking the signal RF : RF signal (Check jitter) FE : FOCUS error

Mechanism deck

I+3V

GND

IOP

I+3V

IOP

GND

FE VC RF

CN105

I+3V IOP

GND

for

MDM-

FE VC

IOP DATA RECORDING AND DISPLAY WHEN OPTICAL PICK-UP AND NON-VOLATILE MEMORY (IC195 OF BD BOARD) ARE REPLACED

The IOP value labeled on the optical pick-up can be recorded in the non-volatile memory. By recording the value, it will eliminate the need to look at the value on the optical pick-up label. When replacing the optical pick-up or non-v olatile memory (IC195 of BD board), record the IOP value on the optical pick-up according to the following procedure.

Record Procedure:

1. While pressing the l AMS L knob and x button, connect the power plug to the outlet, and release the l AMS L knob and x button.

2. Turn the l AMS L knob to display “[Service]”, and press the YES button.

3. Turn the l AMS L knob to display “lop Write” (C28), and press the YES button.

4. The display becomes “Ref=@@@.@” (@ is an arbitrary number) and the numbers which can be changed will blink.

5. Input the IOP value written on the optical pick-up label. To select the number : Turn the l AMS L knob. To select the digit : Press the l AMS L knob.

6. When the YES button is pressed, the display becomes “Measu=@@@.@” (@ is an arbitrary number).

7. As the adjustment results are recorded for the 6 value. Leave it as it is and press the YES button.

8. “Complete!” will be displayed momentarily. The value will be recorded in the non-volatile memory and the display will become “Iop Write”.

9. Press the FILTER button to complete.

Display Procedure:

1. While pressing the l AMS L knob and x button, connect the power plug to the outlet, and release the l AMS L knob and x button.

2. Turn the l AMS L knob to display “[Service]”, and press the YES button.

3. Turn the l AMS L knob to display “lop Read” (C27).

4. “@@.@/##.#” is displayed and the recorded contents are displayed. @@.@ : indicates the IOP value on the optical pick-up label. ##.# : indicates the IOP value after adjustment

5. To end, press the l AMS L knob or MENU/NO button to display “Iop Read”. Then press the FILTER button.

CHECKS PRIOR TO PARTS REPLACEMENT AND ADJUSTMENTS

Before performing repairs, perform the following checks to determine the faulty locations up to a certain extent. Details of the procedures are described in “5. Electrical Adjustments”.

Criteria for Determination

(Unsatisfactory if specified value is not satisfied)

Laser power check (See page 25)

Temp check (See page 25)

Note: The criteria for determination above is intended merely to determine if satisfactory or not, and does not serve as the specified value for adjustments.

When performing adjustments, use the specified values for adjustments.

• 0.9 mW power Specified value : 0.84 to 0.92 mW

• 7.0 mW power Specified value : 6.8 to 7.2 mW

lop (at 7mW)

• Labeled on the optical pickup Iop value ± 10mA

• Unsatisfactory if displayed as T=@@ (##) [NG” NG (@@, ## are both arbitrary numbers)

• Clean the optical pick-up

• Adjust again

• Replace the optical pick-up

• Check for disconnection of the circuits around

D101 (BD board)

• Check the signals around IC101, IC151, CN102, CN103 (BD board)

Measure if unsatisfactory:

RETRY CAUSE DISPLAY MODE

• In this test mode, the causes for retry of the unit during recording can be displayed on the fluorescent indicator tube. During playback, the “track mode” for obtaining track information will be set.

This is useful for locating the faulty part of the unit.

• The following will be displayed : During recording and stop : Retry cause, number of retries, and number of retry errors. During playback : Information such as type of disc played, part played, copyright. These are displayed in hexadecimal.

Procedure:

1. Procedure 1: Press the x button continuously for about 10 seconds.

Procedure 2: Press the LEVEL/DISPLAY/CHAR button while pressing the x button and MENU/NO button.

2. When the mode is set, “RTs 00c 00e 000” is displayed.

3. Press the z REC button to start recording. Then press the X button and start recording.

4. To check the “track mode”, press the H button to start play.

5. To exit the test mode, press the ?/1 button, and turn OFF the power. When “TOC” disappears, disconnect the power plug from the

outlet.

Fig. 1 Reading the Test Mode Display

(During recording and stop)

RTs@@c##e

Fluorescent indicator tube display

@@ : Cause of retry ## : Number of retries

: Number of retry errors

Reading the Retry Cause Display

Higher Bits Lower Bits

Hexadecimal

Bit

Binary

84218421

b7 b6 b5 b4 b3 b2 b1 b0

00000001 00000010 00000100

00001000 00010000 00100000 01000000 10000000

Hexa-

decimal

01 02 04

08 10 20 40 80

Cause of

Retry

shock ader5 Discontinuous address

DIN unlock FCS incorrect IVR rec error CLV unlock Access fault

Fig. 2 Reading the Test Mode Display

(During playback)

@@ ###

Fluorescent indicator tube display

@@ : Parts No. (name of area named on TOC) ## : Cluster

: Sector

$$ : Track mode (Track information such as

When track jump (shock) is detected When ADER was counted more than five times

continuously When ADIP address is not continuous When DIN unlock is detected When not in focus When ABCD signal level exceeds the specified range When CLV is unlocked When access operation is not performed normally



Address

 

Occurring conditions

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 t b6 Lower bit : 2 = 0010 t b1 In this case, the retry cause is combined of “CLV unlock” and “ader5”.

When A2 is displayed: Higher bit : A = 1010 t b7+b5 Lower bit : 2 = 0010 t b1 The retry cause in this case is combined of “access fault”, “IVR rec error”, and “ader5”.

Reading the Retry Cause Display

Higher Bits Lower Bits

Hexadecimal

Bit

Binary

Reading the Display:

Convert the hexadecimal display into binary display. If more than two causes, they will be added.

Example When 84 is displayed:

Higher bit : 8 = 1000 t b7 Lower bit : 4 = 0100 t b2 In this case, as b2 and b7 are 1 and others are 0, it can be determined that the retry cause is combined of “emphasis OFF”, “monaural”, “original”, “copyright exists”, and “write allowed”.

Example When 07 is displayed:

Higher bit : 0 = 1000 t All 0 Lower bit : 7 = 0111 t b0+b1+b2 In this case, as b0, b1, and b2 are 1 and others are 0, it can be determined that the retry cause is combined of “emphasis ON”, “stereo”, “original”, “copyright exists”, and “write prohibited”.

84218421

b7 b6 b5 b4 b3 b2 b1 b0

00000001 00000010 00000100 00001000 00010000 00100000 01000000 10000000

Hexa-

decimal

01 02 04 08 10 20 40 80

When 0

Emphasis OFF Monaural This is 2-bit display. Normally 01. 01:Normal audio. Others:Invalid Audio (Normal) Original Copyright Write prohibited

Details

When 1

Emphasis ON Stereo

Invalid Digital copy No copyright Write allowed

Hexadecimal t Binary Conversion Table

Hexadecimal Binary Hexadecimal Binary

0 0000 8 1000 1 0001 9 1001 2 0010 A 1010 3 0011 B 1011 4 0100 C 1100 5 0101 D 1101 6 0110 E 1110 7 0111 F 1111

SECTION 2

GENERAL

This section is extracted from instruction manual.

121314

SECTION 3

DISASSEMBLY

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

3-1. CASE (4095269)

1 Four screws (Screw (TP), flat head)

3 Case (4095269)

2 Three screws

(Screw (TP), flat head)

3-2. FRONT PANEL SECTION

2 Connector

Claw

(CN801)

1 Connector

(CN800)

3 Wire (flat type)(19 core)(CN2)

Claw

4 Six screws

(BVTP3 × 8)

5 Front panel section

3-3. AU BOARD

8 Wire (flat type) (23 core)

7 Wire (flat type) (27 core)

(CN12)

(CN11)

9 Screw

(BVTP 3 × 8)

6 Connector

(CN700)

5 Connector

(CN401)

4 Connector

(CN403)

3 Connector

(CN404)

2 Connector

(CN200)

q; Four screws

(BVTP 3 × 8)

qs AU board

1 Wire (flat type) (19 core)

(CN2)

qa Seven screws

(BVTP 3 × 8)

3-4. MECHANISM DECK (MDM-7A)

)

4 Remove the mechanism deck

(MDM-7A) to direction of the arrow.

2 Wire (flat type)(23 core)(CN11)

3 Four step screws

(BVTTWH M3)

1 Wire (flat type) (27 core

(CN12)

3-5. BD BOARD

5 Remove the solder (four portions)

1 Wire (flat type)(23 core)

2 Wire (flat type

(27 core)

7 BD board

3 Connector

(CN104)

4 Remove the solder (five portions)

8 Flexible board (CN104)

6 Two screws (BTP 2 × 6)

SECTION 4

TEST MODE

4-1. PRECAUTIONS FOR USE OF TEST MODE

• As loading related operations will be performed regardless of the test mode operations being performed, be sure to check that the disc is stopped before setting and removing it. Even if the EJECT A b utton is pressed while the disc is rotating during continuous playback, continuous recording, etc., the disc will not stop rotating. Therefore, it will be ejected while rotating. Be sure to press the EJECT A button after pressing the MENU/NO button and the rotation of disc is stopped.

4-1-1. Recording laser emission mode

• Continuous recording mode (CREC 1 MODE)

• Laser power check mode (LDPWR CHECK)

• Laser power adjustment mode (LDPWR ADJUS)

• IOP check (Iop compare)

• IOP value non-volatile writing (Iop NV Save)

• Traverse (MO) check (EF MO CHECK)

• Traverse (MO) adjustment (EF MO ADJUS)

• When pressing the REC z button.

4-2. SETTING THE TEST MODE

The following are two methods of entering the test mode. Procedure 1: While pressing the l AMS L knob and x button, connect the power plug to an outlet, and release the l AMS L

knob and x button. When the test mode is set, “[Check]” will be displayed. T urn the l AMS L knob switches between the following three groups; ···y [Check] y [Service] y [Develop] y ···.

Procedure 2: While pressing the l AMS L knob, connect the power plug to the outlet and release the l AMS L knob.

When the test mode is set, “TEMP CHECK” will be displayed. By setting the test mode using this method, only the “Check” group of method 1 can be executed.

4-3. RELEASING THE TEST MODE

Press the REPEAT button. The test mode is released and the unit sets into the STANDBY state.

4-4. BASIC OPERATIONS OF THE TEST MODE

All operations are performed using the l AMS L knob, YES button, and MENU/NO button. The functions of these buttons are as follows.

Function name

MENU/NO button YES button l AMS L knob (right and left) l AMS L knob (push)

Cancels or moves to the next level up in the hierarchy. Establishes. Selects. Establishes the sub menu.

Function

4-5. SELECTING THE TEST MODE

There are 25 types of test mode as shown below. The groups can be switched by turning the l AMS L knob. All of the service adjustments and checks can be performed in the test modes of Service group. There is also the Develop group, but it is not used for service. If the Develop group is set by mistake, immediately press the MENU/NO button to release the group.

Display

AUTO CHECK Err Display TEMP ADJUS LDPWR ADJUS Iop Write Iop NV Save

EF MO ADJUS EF CD ADJUS FBIAS ADJUS AG Set (MO) AG Set (CD) TEMP CHECK LDPWR CHECK EF MO CHECK EF CD CHECK FBIAS CHECK ScurveCHECK VERIFYMODE DETRK CHECK 0920 CHECK Iop Read Iop Compare ADJ CLEAR INFORMATION CPLAY 1 MODE CREC 1 MODE

No.

C01

Auto self-diagnosis

C02

Error history display/delete

C03

Temperature compensation offset adjustment

C04

Laser power adjustment

C05

IOP data writing

C06

The current IOP value is read by the microprocessor and written into nonvolatile memory.

C07

Traverse (MO) check

C08

Traverse (CD) check

C09

Focus bias adjustment

C10

Focus tracking gain adjustment (MO)

C11

Focus tracking gain adjustment (CD)

C12

Temperature compensation offset check

C13

Laser power check

C14

Traverse (MO) check

C15

Traverse (CD) check

C16

Focus bias check

C17

S-curve check

C18

Non-volatile memory check

C19

Detrack check

C25

Outermost circumference check

C26

IOP data display

C27

Comparison with initial IOP value written in non-volatile memory

C28

Initialization of adjustment value in non-volatile memory

C31

Display of version of microprocessor, etc.

C34

Continuous playback mode

C35

Continuous recording mode

Contents

GroupMark

Check

× × × ×

Service

a a a a a

a a a a

a a a a a a a a a a a a

a a a

• For details of each adjustment mode, refer to “5. Electrical Adjustments” on page 22.

• For details of “Err Display” (C02), refer to “Self-Diagnosis Function” on page 4.

• If a different mode has been selected by mistake, press the MENU/NO button to release that mode.

• Modes with (×) in the Mark column are not used for servicing and therefore are not described in detail. If these modes are set accidentally,

press the MENU/NO button to release the mode immediately. Be especially careful not to use a test mode of Develop the unit will not operate normally.

4-5-1. Operating the Continuous Playback Mode

1. Entering the continuous playback mode

1) Set the disc in the unit. (Whichever recordable discs or discs for playback only are available.)

2) Turn the l AMS L knob and display “CPLAY 1 MODE” (C35).

3) Press the YES button to change the display to “CPLAY 1 MID”.

4) When access completes, the display changes to “C = AD = ”.

Note: The numbers “ ” displayed show you error rates and “ADER”.

2. Changing the parts to be played back

1) Press the YES button during continuous playback to change the display as below. The parts to be played back can be moved. “CPLAY 1 MID” t “CPLAY 1 OUT” t “CPLAY 1 IN”

2) When access completes, the display changes to “C = AD = ”.

Note: The numbers “ ” displayed show you error rates and “ADER”.

3. Ending the continuous playback mode

1) Press the MENU/NO button. The display will change to “CPLAY 1 MODE”.

2) Press the EJECT A button and take out the disc.

Note: The playback start addresses for IN, MID, and OUT are as follows.

IN 40h cluster MID 300h cluster OUT 700h cluster

4-5-2. Operating the Continuous Recording Mode (Use only when performing self-recording/palyback check.)

1. Entering the continuous recording mode

1) Set a recordable disc in the unit.

2) Turn the l AMS L knob and display “CREC 1 MODE” (C34).

3) Press the YES button to change the display to “CREC 1 MID”.

4) When access completes, the display changes to “CREC 1 (

Note: The numbers “ ” displayed shows you the recording position addresses.

” and “

REC

” lights up.

2. Changing the parts to be recorded

1) When the YES b utton is pressed during continuous r ecording, the display changes as below. The parts to be recorded can be changed.

“

” goes off during movement.

REC

“CPLAY 1 MID” t “CPLAY 1 OUT” t “CREC 1 IN”

2) When access completes, the display changes to “CREC 1 ( ” and “

Note: The numbers “ ” displayed shows you the recording position addresses.

REC

3. Ending the continuous recording mode

1) Press the MENU/NO button. The display changes to “CREC 1 MODE” and “

2) Press the l AMS L button and take out the disc.

Note 1: The recording start addresses for IN, MID, and OUT are as follows.

Note 2: The MENU/NO button can be used to stop recording anytime. Note 3: Do not perform continuous recording for long periods of time above 5 minutes. Note 4: During continuous recording, be careful not to apply vibration.

IN 40h cluster MID 300h cluster OUT 700h cluster

” lights up.

” goes off.

REC

4-6. FUNCTIONS OF OTHER BUTTONS

Function

PLAY

STOP FF FR REC MODE

(other models/SF EDIT/SCROLL) PLAY MODE DISPLAY EJECT POWER/REPEAT

Sets continuous playback when pressed in the STOP state. When pressed during continuous playback, the tracking servo turns ON/OFF.

Stops continuous playback and continuous recording. The sled moves to the outer circumference only when this is pressed. The sled moves to the inner circumference only when this is pressed. Switches between the pit and groove modes when pressed.

Switches the spindle servo mode (CLV-S y CLV-A). Switches the displayed contents each time the button is pressed Ejects the disc Releases the test mode

Contents

4-7. TEST MODE DISPLAYS

The DISPLAY/CHAR button is used to change the display mode. Each time the DISPLA Y/CHAR button is pr essed, the display changes in the following order.

Order

Mode display

Error rate display

Address display

Auto gain display

Detrack display

IVR display

Display of C1 error and jitter

Display of AD error and jitter

Details

Display

CPLAY (xxxx C=xxxxAD=xx hxxxx sxxxx AG=xx/xx[xx] ADR=xx#0000 [xx][xx][xx] Jxxxx Cxxxx Jxxxx AD=xx

When C-PLAY or C-REC starts, the display is forcibly switched to one of “2” as the initial mode.

Supplementary explanations of each display

1. Mode display A display such as “TEMP ADJUST” or “CPLAY 1 MODE” appears.

2. Error rate display The error rate is displayed as shown below.

C=xxxxAD=xx

C= indicates C1 error, AD= indicates ADER.

3. Address display The address is displayed as shown below.

h=xxxx s=xxxx (pit of recordable disc and playback-only disc)

h=xxxx a=xxxx (groove of recordable disc) h= indicates header address, s= indicates SUBQ address, a= indicates ADIP address. * If the address cannot be read, “-” appears.

Displays other than the above are not used for service.

4-8. MEANINGS OF OTHER DISPLAYS

Display

N X

REC

SYNC (other models/TOC EDIT) L. SYNC (other models/A.SPACE) OVER B/1 (REP portion) A-REP TRACK/(LP)4/calender frame DISC/LP2 SLEEP/SHUF MONO

When Lit

Servo ON Tracking servo OFF Recording mode ON CLV low speed mode ABCD adjustment completed Tracking offset cancel ON Tracking auto gain OK Focus auto gain OK Pit High reflection CLV-S CLV LOCK

Contents

When Off

Servo OFF Tracking servo ON Recording mode OFF CLV normal mode

Tracking offset cancel OFF

Groove Low reflection CLV-A CLV UNLOCK

4-9. AUTO DIAGNOSIS FUNCTION

This test mode automatically performs C-REC and C-PLAY and checks mainly the characteristics of the optical pick-up. To ex ecute the test mode, first check the laser power and perform AUTO CHECK after Iop Compare.

[Operation Procedure]

1. Press the YES b utton. If “LDPWR perform Iop Compare. Then, repeat this step.

2. If there is a disc in the mechanism deck, the disc is forcibly ejected. After “DISC IN” appears, load a recordable test disc (MDW-74/GA-1).

3. When the disc is loaded in step 2, the check automatically starts.

4. While “XX CHECK” is displayed, the check of the item shown in “XX” is in progress. After “06 check” is complete, eject the disc loaded in step 2. When “DISC IN” appears, load the TDYS-1 check disc (MD).

5. After the disc loaded in step 4 is loaded, the check automatically restarts from “07 CHECK”.

6. After the check of item 12 is complete, “OK” or “NG” appears. When all items are OK, “CHECK ALL OK” appears. If e ven one of t he items failed, “NG: xxxx” appears.

” appears, which means the laser power has not been checked, first check the laser po wer and

When “CHECK ALL OK” appears, there is no problem in the optical pick-up. Check the operations of the spindle motor, sled motor, etc. If “NG: xxxx” appears, there is an abnormality in the optical pick-up. Replace the optical pick-up.

4-10. INFORMATION

The version of the software is displayed.

[Operation Procedure]

1. When “INFORMATION” appears, press the YES button.

2. The version of the software is displayed.

3. Press the MENU/NO button to end this mode.

4-11. MEASURE WHEN “MEMORY NG” APPEARS

If there is an abnormality in the data of the non-volatile memory , “E001” or “MEMORY NG” appears so that the MD mechanism deck does not continue to be operated. If either of these messages appears, immediately enter the test mode and perform the following operation.

[Operation Procedure]

1. Enter the test mode. (Refer to Section 4-2.)

2. Normally, the test mode selection display appears. If there is an abnormality in the non-volatile memory, the message “INIT EEP?” appears.

3. Press the x button and the EJECT A button at the same time.

4. Turn the l AMS L knob to select “MDM-7A”.

5. Press the l AMS L knob. After the non-volatile memory is re written, the mode returns to the normal test mode and the test mode selection display appears.

SECTION 5

ELECTRICAL ADJUSTMENTS

5-1. PARTS REPLACEMENT AND ADJUSTMENT

If a defect such as dropout caused by the OP is found, check the following.

Check Procedure Before Replacement

Start

Laser power check

Iop Compare

AUTO CHECK

Mechanism check of sled, etc. Other cause is likely.

Replace the OP or replace the MDM.

Flow During Adjustment

Start

Replace IC195.

Replace either OP or IC195. ADJ CLEAR

Replace either IC101, IC195 or D101.

Replace either OP, IC190 or IC195.

Replace either

OP, IC102, IC190 or IC195.

YES

After turning on the power again, initialize EEPROM.

TEMP ADJUST

LDPWR ADJUST

Iop NV Save

Replace either

OP, IC101, IC151 or IC195.

YES

Replace the OP.

Replace the spindle motor. spdl change in Err Display mode

AUTO CHECK

End adjustment.

YES

EF MO, CD ADJUST

FBIAS ADJUST

AG SET (MO), (CD)

op change in Err Display mode

Iop Write

+ 51 hidden pages

Sony MDSJB-940 Service manual

TABLE OF CONTENTS

SELF-DIAGNOSIS FUNCTION

SERVICE NOTE

GENERAL

DISASSEMBLY

TEST MODE

ELECTRICAL ADJUSTMENTS