Sony HCD-MD373 Checks Prior to Repairs, Temperature Compensation Offset Check, Laser Power Check

Page 33

5-6. CHECKS PRIOR TO REPAIRS

These checks are performed before replacing parts according to “approximate specifications” to determine the faulty locations. For details, refer to “Checks Prior to Parts Replacement and Adjustments” (See page 13).

5-6-1. Temperature Compensation Offset Check

When performing adjustments, set the internal temperature and room temperature to 22 to 28°C.

Checking Procedure:

1.Press the =0/MD/CD/TUNING – button or )+/ MD/CD/TUNING + button to display “TEMP CHECK”.

2.Press the ENTER/YES “R” button.

3.“T=@@(##) [OK]” should be displayed. If “T=@@ (##) [NG]” is displayed, it means that the results are bad.

(@@ indicates the current value set, and ## indicates the value written in the non-volatile memory.)

5-6-2. Laser Power Check

Before checking, check the IOP value of the optical pick-up. (Refer to 5-8. Recording and Displaying IOP Information.)

Laser power meter

Optical pick-up objective lens

Digital volt meter

BD (MD) board

CN110 pin 5 (I+3V)

CN110 pin 4 (IOP)

Connection :

Checking Procedure:

1.Set the laser power meter on the objective lens of the optical pick-up. (When it cannot be set properly, press the =0/ MD/CD/TUNING – button or )+/MD/CD/TUNING +

button continuously to move the optical pick-up.)

Connect the digital volt meter to CN110 pin 5 (I+3V) and CN110 pin 4 (IOP).

2.Then, press the =0/MD/CD/TUNING – button or )+/MD/CD/TUNING + button and display “LDPWR CHECK”.

3.Press the ENTER/YES “R” button once and display “LD 0.9 mW $ ”. Check that the reading of the laser power meter be- come 0.84 to 0.92 mW.

4.Press the ENTER/YES “R” button once more and display “LD 7.0 mW $ ”. Check that the reading the laser power meter and digital volt meter satisfy the specified value.

Specified Value :

Laser power meter reading : 7.0 ± 0.2 mW

Digital voltmeter reading : Optical pick-up displayed value ± 10%

(Optical pick-up label)

KMS260A

(For details of the method for checking

27X40

this value, refer to “5-8. Recording and

Displaying IOP Information”.)

B0825

 

 

 

N

 

Iop = 82.5 mA in this case

Iop (mA) = Digital voltmeter reading (mV)/1 (Ω)

5.Press the MENU/NO “R” button and display “LDPWR CHECK” and stop the laser emission.

(The MENU/NO “R” button is effective at all times to stop the laser emission.)

Note 1: After step 4, each time the ENTER/YES “R” button is pressed, the display will be switched between “LD 0.7 mW

$ ”, “LD 6.2 mW $ ”, and “LD WP $ ”. Nothing needs to be performed here.

5-6-3. Traverse Check

Connection :

Oscilloscope

BD (MD) board

CN110 pin 3 (TE)

CN110 pin 1 (VC)

V : 0.5 V/div

H : 10 ms/div

Input : DC mode

Checking Procedure:

1.Connect an oscilloscope to CN110 pin 3 (TE) and CN110 pin 1 (VC) of the BD (MD) board.

2.Load a disc (any available on the market). (Refer to Note 1.)

3.Press the )+/MD/CD/TUNING + button continuously and move the optical pick-up outside the pit.

4.Press the =0/MD/CD/TUNING – button or )+/ MD/CD/TUNING + button and display “EF MO CHECK”.

5. Press the ENTER/YES “R” button and display “EFB =

MO-

R”.

 

 

 

(Laser power READ power/Focus servo ON/tracking servo OFF/ spindle (S) servo ON)

6.Observe the waveform of the oscilloscope, and check that the specified value is satisfied. Do not press the =0/MD/CD/

TUNING – button or)+/MD/CD/TUNING + button. (Read power traverse checking)

(Traverse Waveform)

A

VC

B

Specified value : Below 10% offset value

 

Offset value (%) = IA – BI X 100

 

2 (A + B)

 

7. Press the ENTER/YES “R” button and display “EFB =

MO-

W”.

 

8.Observe the waveform of the oscilloscope, and check that the specified value is satisfied. Do not press the =0/MD/CD/

TUNING – button or)+/MD/CD/TUNING + button. (Write power traverse checking)

(Traverse Waveform)

A

VC

B

Specified value : Below 10% offset value

Offset value (%) = IA – BI X 100 2 (A + B)

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Contents 928-998-12 SpecificationsSELF-DIAGNOSIS Function Items of Error History Mode Items and Contents Flexible Circuit Board Repairing AEP, UKHK, SP, MY, AR, AUS, KR, JE Disassembly Table of ContentsDiagrams Exploded ViewsCleaning the Optical Pickup CD Player Drawing OUT the Tray During Power OFFSection Servicing Note Removing the Indication Plate FLService Position the Power Board Hot Reset Cold ResetLED and Fluorescent Indicator Tube All Lit, Key Check Mode Change-over of AM tuner Step between 9kHz and 10kHzError History Display Mode Aging ModeReading the BD Error History Display Reading the Mechanism Error History DisplayJIG for Checking BD MD Board Waveform IOPTEO Record Precedure Forced Reset Checks Prior to Parts Replacement and AdjustmentsREC/PLAY Main Board Component SideTuning +/MD/CD/TUNING + Retry Cause Display ModeHexadecimal nBinary Conversion Table Section General Location of Parts and ControlsFront Panel Page Page Case Section DisassemblyBack Panel Front PanelCD Mechanism Deck Main Board and Power TransformerTRAY, Gear and CAM CD Base UnitOptical PICK-UP Section of CD KSS-213BA/F-NP MD Mechanism Deck BD CD BOARD, Spindle Motor M101 and Sled Motor M102Set the shaft of Cam gear to Spindle Motor M901 and Sled Motor M902 MD Over Write Head Optical PICK-UP of MD KMS-260B/J1NPrecautions for USE of Test Mode Section Test ModeSetting the Test Mode Exiting the Test ModeDisplay Contents Mark Group Selecting the Test ModeNon-Volatile Memory Mode EEP Mode Operating the Continuous Playback ModeMID OUTFunctions of Other Buttons Test Mode DisplaysMeanings of Other Displays MD Section Parts Replacement and Adjustment Section Electrical AdjustmentsPrecautions for USE of Optical PICK- UP KMS-260B Precautions for Checking Laser Diode EmissinonPrecautions for Adjustments Creating Continuously Recorded DiscLaser Power Check Temperature Compensation Offset CheckChecks Prior to Repairs Specified ValueCD Error Rate Check Play Checking MO Error Rate CheckFocus Bias Check Self-Recording/playback CheckTemperature Compensation Offset Adjutment Initial Setting of Adjustment ValueLaser Power Adjustment Recording and Displaying the IOP InformationCheck Traverse AdjustmentPress the ENTER/YES R button, display EFB = Focus Bias AdjustmentAuto Gain Control Output Level Adjustment Error Rate CheckCD Auto Gain Control Output Level Adjustment MO Auto Gain Control Output Level AdjustmentCD Section Adjusting Points and Connecting PointsCurve Check RF Level CheckCircuit Boards Location HCD-MD373 Section DiagramsHCD-MD373 Block Diagrams BD CD SectionREC BD MD /2D/A Converter BD CD Section Main SectionBD MD 1/2 Section Waveforms BD CD SectionBD MD 2/2 Section Main 3/3 SectionPrinted Wiring Board BD CD Section See page 40 for Circuit Boards LocationMain Board Schematic Diagram BD CD Section Semiconductor Location Printed Wiring Board BD MD SectionSchematic Diagram BD MD /2 MD Digital Board Schematic Diagram SP Section Printed Wiring Board SP Section Printed Wiring Board Main Section See page 68 for IC Block Diagrams Schematic Diagram Main /3HCD-MD373 HCD-MD373 See page 45 for Waveforms See page 67 for IC Block Diagrams Schematic Diagram MD Digital SectionPrinted Wiring Board MD Digital Section Schematic Diagram AMP Section Printed Wiring Board AMP Section Schematic Diagram Panel Section Printed Wiring Board Panel Section Schematic Diagram Power Section Printed Wiring Board Power Section AEP, UKExcept AEP, UK Voltage Selector Printed Wiring Board BD Switch Section Schematic Diagram BD Switch SectionSchematic Diagram Loading Section Printed Wiring Board Loading SectionBD MD Board 1/2 IC101 CXA2523AR IC Block DiagramsBD MD Board 2/2 IC121 CXD2654R IC152 BH6511FS-E2BD CD Board IC101 CXD2587Q C103 CXA2568M-T6 MD Digital BoardIC153 LB1830M-S-TE-L Main Board 3/3 IC171 LB1641 Main Board 1/3 IC302 MC14052BMain Board 2/3 IC301 M62428AFP IC931 M62016L IC PIN Functions IC101 Digital Signal Processor CXD2587Q Bdcd boardAdio RfdcAVSS0 IgenIC101 RF Amplifier CXA2523AR Bdmd board MNT1 Shck MNT0 FOKMNT2 Xbusy MNT3 SlocAvdd MvciRFI AvssSprd FS4Spfd FginIC501 Master Control M30620ECFP-A21 Main board Stereo CD-RESETTuned ST-CECase and Front Panel Section Section Exploded Views59 #3 Chassis SectionMD Mechanism Deck MDM-5A 113 110 107125 126 106 105 MD Base Unit MBU-5A CD Mechanism Deck CDM55A-5SBD32 255 256 257 253 254 CD Base Unit BU-5SBD32252 254 258 251CD Mechanism Deck CDM55C-5BD32 355 356 357 353 354 CD Base Unit BU-5BD32352 354 358 351Section Electrical Parts List AMP AMP BD CD BD CD BD MD Inductor Chip BD MD MD Digital2SJ278MYTR 2SK1764KYTR ResistorMD Digital Loading Main Main EP1 Ground TerminalTerminal BOARD, Ground EP2Description Remark R402 249-417-11 Panel Indicator TUBE, FluorescentPanel BOARD, Complete Jack LINE-INPanel Power TRANSFORMER, SUB Power Switch Voltage SelestorPIN, Connector 7P SWITCH, Push 1 KEYHardware List SCREW,PRECISION +PScrew +B Memo HCD-MD373 Revision History

HCD-MD373 specifications

The Sony HCD-MD373 is a compact mini audio system that offers an impressive blend of sound quality, versatility, and advanced technology, making it an ideal choice for audio enthusiasts and casual listeners alike. One of the standout features of the HCD-MD373 is its MiniDisc recorder/player, a legacy technology that allows users to record high-quality audio onto MiniDiscs, providing an alternative to traditional CDs and cassettes. This feature is particularly appealing for those looking to capture live music or create personalized playlists.

Another notable aspect of the HCD-MD373 is its integrated CD player, which supports a variety of formats including CD, CD-R, and CD-RW. This versatility means that users can enjoy their favorite albums without the hassle of switching devices. The audio system also includes a built-in AM/FM tuner, enabling users to easily tune into their favorite radio stations and enjoy live broadcasts.

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In terms of connectivity, the HCD-MD373 offers multiple inputs and outputs, including audio line-in, headphone jacks, and a digital optical output. These features make it easy to connect external devices such as MP3 players, smartphones, or even home theater systems. Additionally, the audio system supports various playback options, including shuffle and repeat modes, providing enhanced flexibility for users.

The design of the HCD-MD373 is sleek and modern, with a compact form factor that allows it to fit seamlessly into any living space. Its user-friendly interface, complete with an LCD display, makes it easy to navigate and control playback settings. Overall, the Sony HCD-MD373 is a testament to Sony's commitment to quality audio experiences, combining innovative features, robust technology, and elegant design into a single, powerful audio system. Whether enjoying a quiet evening at home or hosting a gathering with friends, the HCD-MD373 is sure to deliver satisfying sound and performance.
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