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MDS-JB920 SERVICE MANUAL US Model Canadian Model AEP Model UK Model Model Name Using Similar Mechanism MDS-JE520 U.S. and foreign patents licensed form Dolby Laboratories Licensing Corporation. MD Mechanism Type MDM-5A Optical Pick-up Type KMS-260A/J1N SPECIFICATIONS System MiniDisc digital audio system...
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General Supplied accessories Power requirements Audio connecting cords (2) Optical cable (1) Where purchased Power requirements Remote commander (remote) RM-D17M (1) Continental Europe and UK 220 – 230 V AC, 50/60 Hz R6 (size-AA) batteries (2) U.S.A and Canada 120 V AC, 60 Hz Design and specifications are subject to change without notice.
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Items of Error History Mode Items and Contents Selecting the Test Mode Display Details of History total rec Displays the recording time. Displayed as “rππππππh”. The displayed time is the total time the laser is set to the high power state. This is about 1/4 of the actual recording time.
SECTION 1 SERVICING NOTES TABLE OF CONTENTS SAFETY CHECK-OUT After correcting the original service problem, perform the follow- ing safety check before releasing the set to the customer: SERVICING NOTES ..........4 Check the antenna terminals, metal trim, “metallized” knobs, screws, and all other exposed metal parts for AC leakage.
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OPERATION. REPLACE THESE COMPONENTS WITH DE FONCTIONNEMENT. NE REMPLACER CES COM- SONY PARTS WHOSE PART NUMBERS APPEAR AS POSANTS QUE PAR DES PIÈCES SONY DONT LES SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB- NUMÉROS SONT DONNÉS DANS CE MANUEL OU LISHED BY SONY.
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JIG FOR CHECKING BD BOARD WAVEFORM The special jig (J-2501-149-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) : TRK error signal (Traverse adjustment) VC : Reference level for checking the signal...
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IOP Data Recording and Display When Pickup and Non-volatile Memory (IC171 of BD board) are Replaced The IOP value labeled on the 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 label of the optical pick-up.
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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 Measure if unsatisfactory: (Unsatisfactory if specified value is not satisfied) Laser power check •...
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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 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. •...
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Reading the Retry Cause Display Higher Bits Lower Bits Hexa- Details Hexadecimal decimal When 0 When 1 b7 b6 b5 b4 b3 b2 b1 b0 Binary Emphasis OFF Emphasis ON Monaural Stereo This is 2-bit display. Normally 01. 01:Normal audio. Others:Invalid Audio (Normal) Invalid Original...
SECTION 3 DISASSEMBLY • This set can be disassembled in the order shown below. CASE (4095269) FRONT PANEL SECTION (Page 14) (Page 15) MAIN BOARD (Page 15) MECHANISM SECITON (MDM-5A) SLIDER (CAM) (Page 16) (Page 16) BASE UNIT (MBU-5A), BD BOARD SW BOARD, LOADING MOTOR (M103) (Page 17) (Page 17)
SECTION 4 TEST MODE 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. [ EJECT] §...
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5. SELECTING THE TEST MODE [ AMS ] There are 31 types of test modes as shown below. The groups can be switched by rotating the ≠ ± knob. After selecting the [YES] [ AMS ] ± group to be used, press the button. After setting a certain group, rotating the ≠...
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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.) [ AMS ] ± (2) Rotate the ≠ knob and display “CPLAY MODE” (C30). [YES] (3) Press the button to change the display to “CPLAY MID”.
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6. FUNCTIONS OF OTHER BUTTONS Function Contents 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.
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MEANINGS OF OTHER DISPLAYS Contents Display When Lit When Off · During continuous playback (CLV: ON) STOP (CLV: OFF) Tracking servo OFF Tracking servo ON Recording mode ON Recording mode OFF –SYNC CLV low speed mode CLV normal mode A.SPACE ABCD adjustment completed OVER Tracking offset cancel ON...
SECTION 5 ELECTRICAL ADJUSTMENTS 1. PARTS REPLACEMENT AND ADJUSTMENT • Check and adjust the MDM and MBU as follows. The procedure changes according to the part replaced • Abbreviation : Optical pick-up OWH : Overwrite head • Temperature compensation offset check •...
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2. PRECAUTIONS FOR CHECKING LASER DIODE 4. Use the following tools and measuring devices. • Check Disc (MD) TDYS-1 EMISSINON (Parts No. 4-963-646-01) To check the emission of the laser diode during adjustments, never • TEST DISK (MDW-74/AU-1) (Parts No. 8-892-341-41) view directly from the top as this may lose your eye-sight.
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[YES] 6. CHECK PRIOR TO REPAIRS Note 1: After step 4, each time the button is pressed, the display will be switched between “LD 0.7 mW $ ”, “LD 6.2 mW $ These checks are performed before replacing parts according to ”, and “LD Wp ”.
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[YES] 6-4. Focus Bias Check 9. Press the button display “EFB = MO-P”. Then, the optical pick-up moves to the pit area automatically Change the focus bias and check the focus tolerance amount. and servo is imposed. Checking Procedure : 10.
7. INITIAL SETTING OF ADJUSTMENT VALUE 9. TEMPERATURE COMPENSATION OFFSET ADJUTMENT Note: Save the temperature data at that time in the non-volatile memory Mode which sets the adjustment results recorded in the non-volatile as 25 ˚C reference data. memory to the initial setting value. However the results of the tempera- Note : ture compensation offset adjustment will not change to the initial setting 1.
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[ AMS ] 11. TRAVERSE ADJUSTMENT 7. Then, rotate the ≠ ± knob and display “LDPWR CHECK” (C02). [YES] Note 1:Data will be erased during MO reading if a recorded disc is 8. Press the button once and display “LD 0.9 mW $ ”.
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[ AMS ] [YES] 8. Rotate the ≠ ± knob so that the waveform of the 18. Press the button, display “EFB = SAV” for a mo- oscilloscope becomes the specified value. ment and save the adjustment results in the non-volatile [ AMS ] (When the ≠...
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13. ERROR RATE CHECK 15. AUTO GAIN CONTROL OUTPUT LEVEL 13-1. CD Error Rate Check ADJUSTMENT Checking Procedure : Be sure to perform this adjustment when the pickup is replaced. 1. Load a check disc (MD) TDYS-1. If the adjustment results becomes “Adjust NG!”, the pickup may [ AMS ] ±...
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16. ADJUSTING POINTS AND CONNECTING POINTS [BD BOARD] (SIDE A) CN101 D101 CN110 I+3V NOTE IC171 [BD BOARD] (SIDE B) IC101 IC121 IC192 Note: It is useful to use the jig. for checking the waveform. (Refer to Servicing Notes on page 6.) –...
SECTION 6 DIAGRAMS 6-1. IC PIN FUNCTION DESCRIPTION • BD BOARD IC101 CXA2523AR (RF AMP, FOCUS/TRACKING ERROR AMP) Pin No. Pin Name Function I-V converted RF signal I input from the optical pick-up block detector I-V converted RF signal J input from the optical pick-up block detector Middle point voltage (+1.65V) generation output terminal 4 to 9 A to F...
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• BD BOARD IC121 CXD2654R (DIGITAL SIGNAL PROCESSOR, DIGITAL SERVO PROCESSOR, EFM/ACIRC ENCODER/DECODER, SHOCK PROOF MEMORY CONTROLLER, ATRAC ENCODER/DECODER) Pin No. Pin Name Function Focus OK signal output to the system controller (IC800) MNT0 (FOK) “H” is output when focus is on (“L”: NG) MNT1 (SHOCK) Track jump detection signal output to the system controller (IC800) MNT2 (XBUSY)
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Pin No. Pin Name Function Address signal output to the D-RAM (IC124) XRAS Row address strobe signal output to the D-RAM (IC124) “L” active Write enable signal output to the D-RAM (IC124) “L” active Two-way data bus with the D-RAM (IC124) I (S) MVCI Digital in PLL oscillation input from the external VCO Not used (fixed at “L”)
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Pin No. Pin Name Function SRDR Sled servo drive PWM signal (–) output to the BH6511FS (IC152) SFDR Sled servo drive PWM signal (+) output to the BH6511FS (IC152) SPRD Spindle servo drive PWM signal (–) output to the BH6511FS (IC152) SPFD Spindle servo drive PWM signal (+) output to the BH6511FS (IC152) I (S)
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• MAIN BOARD IC100 CXD8607N (A/D CONVERTER) Pin No. Pin Name Function INRP R-ch analog signal (–) input terminal INRM R-ch analog signal (+) input terminal REFI Reference voltage (+3.3V) input terminal (for A/D converter section) AVDD — Power supply terminal (+5V) (for A/D converter section, analog system) AVSS —...
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Pin No. Pin Name Function Power supply terminal (+5V) (for L-ch side D/A converter section, analog system) AVDDL — Not used (open) L-ch PLM signal 1 output terminal Not used (open) Power supply terminal (+5V) (for L-ch side D/A converter section, digital system) VDD2 —...
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• MAIN BOARD IC800 M30610MCA-264FP (SYSTEM CONTROLLER) Pin No. Pin Name Function JOG1 JOG dial pulse input from the rotary encoder (S713 ≠ AMS ±) JOG0 JOG dial pulse input from the rotary encoder (S713 ≠ AMS ±) Monitor output terminal for the test C1 error rate is output when test mode ADER Monitor output terminal for the test ADER is output when test mode Subcode Q sync (SCOR) input from the CXD2654R (IC121)
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MDS-JB920 Pin No. Pin Name Function Pin No. Pin Name Function Laser power select signal output to the CXD2654R (IC121) and HF module switch circuit Optical in 1/2 or coaxial in selection signal output to the digital input selector (IC300)
• Circuit Boards Location 6-4. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS Note on Schematic Diagram: Note on Printed Wiring Boards: • All capacitors are in µF unless otherwise noted. pF: µµF • X : parts extracted from the component side. AC board 50 WV or less are not indicated except for electrolytics •...
MDS-JB920 6-9. SCHEMATIC DIAGRAM – MAIN Section (2/3) – • See page 72 and 73 for IC Block Diagrams. (Page 51) (Page 56) (Page 59) Note: • Voltages and waveforms are dc with respect to ground in The components identified by mark ! or dotted Les composants identifiés par une marque ! sont...
MDS-JB920 6-10. SCHEMATIC DIAGRAM – MAIN Section (3/3) – • • See page 53 and 54 for Waveforms. See page 72 and 73 for IC Block Diagrams. (Page 58) (Page 68) (Page 68) (Page 56) Note: • Voltages and waveforms are dc with respect to ground in playback mode.
MDS-JB920 6-14. SCHEMATIC DIAGRAM – PANEL Section – • See page 54 for Waveforms. (Page 60) (Page 60) (Page 55) (Page 56) Note: • Voltages and waveforms are dc with respect to ground in playback mode. no mark : Stop –...
SECTION 7 EXPLODED VIEWS NOTE: • -XX and -X mean standardized parts, so they • Items marked “*” are not stocked since they The components identified by mark ! or dotted line with mark may have some difference from the original are seldom required for routine service.
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Description Remark 4-998-590-01 PANEL, FRONT (BLACK) 4-997-211-01 BUTTON (MODE) (BLACK) 4-998-590-31 PANEL, FRONT (SILVER) 4-997-211-21 BUTTON (MODE) (SILVER) 4-942-568-41 EMBLEM (NO.5), SONY 4-996-690-11 LID (CARTRIDGE) (SILVER) 4-998-607-01 INDICATOR (POWER) 4-996-690-21 LID (CARTRIDGE) (BLACK) 4-998-606-01 INDICATOR (MEGA) 4-976-593-01 SPRING (LID), TORSION...
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(4) BASE UNIT SECTION (MBU-5A) HR901 not supplied not supplied M101 S102 M102 The components identified by Les composants identifiés par une mark ! or dotted line with marque ! sont critiques pour la mark ! are critical for safety. sécurité.
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SECTION 8 ELECTRICAL PARTS LIST NOTE: • Due to standardization, replacements in the • Items marked “*” are not stocked since they The components identified by mark ! or dotted line with mark parts list may be different from the parts speci- are seldom required for routine service.
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