Sony MDS-S50 MDS-JE470 Section Service Notes, Safety CHECK-OUT, Leakage, US model only

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MDS-JE470

SECTION 1

SERVICE NOTES

SAFETY CHECK-OUT

(US model only)

After correcting the original service problem, perform the fol- lowing 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). 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 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 pas- sive 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 1.5kΩ voltmeter

(0.75V)

Earth Ground

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

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.

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.

NOTES ON LASER DIODE EMISSION CHECK

Never look into the laser diode emission from right above when checking it for adjustment. It is feared that you will lose your sight.

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.

This 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 radia- tion 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.

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ!

LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0 SUR LES

DIAGRAMMES SCHÉMATIQUES 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.

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Contents 873-891-11 SpecificationsThree- or five Digit code Cause/Remedy Message MDS-JE470SELF-DIAGNOSIS Function Items of Error History Mode Items and Contents Disassembly Table of ContentsDiagrams Exploded ViewsSafety CHECK-OUT MDS-JE470 Section Service NotesFlexible Circuit Board Repairing LeakageIOP JIG for Checking BD Board WaveformRecord Precedure Optical PICK-UP Block Type Discrimination KSN-260EMain Board Component Side Checks Prior to Parts Replacement and AdjustmentsForced Reset Bit Binary Retry Cause Display ModeHexadecimal Binary Bit When BinaryHigher Bits Lower Bits Hexa Details Button Descriptions MDS-JE470 Section GeneralDisassembly Flow MDS-JE470 Section DisassemblyFront Panel Section PT BOARD, VOL-SEL Board SP model Main BoardOver Light Head HR901, BD Board Mechanism Deck Section MDM-7ALoading Motor Assy M103 Holder AssyOptical PICK-UP Sled Motor Assy M102, SliderSpindle Moter Assy M101 Precautions for USE of Test Mode MDS-JE470 Section Test ModeSetting the Test Mode Exiting the Test ModeDisplay Selecting the Test ModeMENU/NO Operating the Continuous Playback ModeMode display Test Mode DisplaysError rate display Functions of Other ButtonsMeanings of Other Displays When Memory NG is DisplayedAutomatic SELF-DIAGNOSIS Function InformationCheck before replacement MDS-JE470 Section Electrical AdjustmentsParts Replacement and Adjustment Adjustment flow Precautions for Adjustments Precautions for Checking Laser Diode EmissionPrecautions for USE of Optical PICK- UP KMS-260B/260E Checks Prior to Repairs Using the Continuously Recorded DiscOther Checks Auto CheckTraverse Check Traverse WaveformCD Error Rate Check Play Check MO Error Rate CheckFocus Bias Check Self-Recording/playback CheckLaser Power Adjustment Initial Setting of Adjustment ValueTemperature Compensation Offset Adjutment Iop NV Save Traverse AdjustmentFocus Bias Adjustment Auto Gain Control Output Level Adjustment Error Rate CheckCD Auto Gain Control Output Level Adjustment MO Auto Gain Control Output Level AdjustmentAdjusting Points and Connecting Points Circuit Boards Location MDS-JE470 Section DiagramsFor printed wiring boards For schematic diagramsBD Board Main BoardIC190 Block Diagrams BD SectionIC171 IC1 2/2 Main SectionIC360 2/2 Semiconductor SemiconductorOVERBoard Board Main Display Board See page 51 for IC Block Diagrams Schematic Diagram Main /2IC1 KEY-SW Board Indicator Tube Schematic Diagram Display Section230V PT BoardSchematic Diagram Power Section IC101 CXA2523AR BD Board IC Block DiagramsIC500 AK4524 Main Board Pin No Pin Name Description IC PIN Function DescriptionIC101 CXA2523AR RF Amplifier BD Board Sqsy Pin No Pin Name DesriptionMvci Abbreviation EFM Eight to Fourteen Modulation IC1 M30803MG-107FP System Control Main Board ADA. Latch STB Chassis Section Section Exploded ViewsFL750 Mechanism MDM-7A M101 Coils Electrical Parts ListMetal Chip MDS-JE470 KEY-SW Main DisplayCN2 MDS-JE470 MainTC7WHU04FUTE12R Screw +KTP 2X6 TYPE2 NON-SLIT MDS-JE470 Main VOL-SELMDS-JE470 MDS-JE470 Revision History

MDS-S50 specifications

The Sony MDS-S50 is a pinnacle of MiniDisc technology, offering audiophiles a compact and reliable way to enjoy high-quality audio. Launched in the early 2000s, it epitomizes the innovation that Sony was known for during this period, combining functionality with sleek design.

One of the primary features of the MDS-S50 is its ability to record in SP (Standard Play) mode, which delivers high-resolution audio at 64 kbps, and LP (Long Play) mode for extended recording times. This flexibility makes it suitable for various listening preferences, whether for critical listening or casual playback during everyday activities. The device harnesses the precision of digital audio encoding, ensuring minimal loss of sound quality.

The MDS-S50 stands out with its direct digital recording capabilities. By connecting to external audio sources via optical or coaxial digital inputs, users can preserve the integrity of the original sound. This feature is particularly appealing for those who want to capture live recordings or transfer vinyl records and CDs to the MiniDisc format without degradation.

The inclusion of a user-friendly interface, with an intuitive remote control and well-organized menu systems, enhances the experience for users. The display panel gives clear information on track titles, remaining recording time, and other essential details, allowing for seamless navigation through complex playlists or recording options.

Another notable technology in the MDS-S50 is the ATRAC (Adaptive Transform Acoustic Coding) compression algorithm, developed by Sony. This proprietary encoding format optimizes sound quality while significantly reducing file sizes. The result is a perfect balance between audio fidelity and efficient storage, which was a major advantage during the era of burgeoning digital music.

Furthermore, the MDS-S50 boasts a durable build quality, designed to withstand transport and everyday use. Its compact size, combined with lightweight materials, allows users to take it on the go while not compromising on audio quality.

Ultimately, the Sony MDS-S50 remains a beloved device among music enthusiasts. With its combination of high-quality recording capabilities, advanced digital encoding technology, and user-friendly features, it represents a unique chapter in the evolution of portable audio. Whether used as a standalone player or part of a larger audio setup, it delivers a level of performance that still resonates with those who appreciate the art of music.
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