Sony MDS-JB920 Focus Bias Check, Play Checking MO Error Rate Check, CD Error Rate Check

Page 26

9.Press the [YES] button display “EFB = MO-P”.

Then, the optical pick-up moves to the pit area automatically and servo is imposed.

10.Observe the waveform of the oscilloscope, and check that the specified value is satisfied. Do not rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob.

(Traverse Waveform)

A

VC

B

Specified value : Below 10% offset value

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

11.Press the [YES] button display “EF MO CHECK” The disc stops rotating automatically.

12.Press the [ÊÊÊÊÊEJECT]¤ button and remove the disc.

13.Load the check disc (MD) TDYS-1.

14.Roteto the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “EF CD CHECK” (C04).

15.Press the [YES] button and display “EFB = CD”. Servo is imposed automatically.

16.Observe the waveform of the oscilloscope, and check that the specified value is satisfied. Do not rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob.

(Traverse Waveform)

A

VC

B

Specified value : Below 10% offset value

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

17.Press the [YES] button and display “EF CD CHECK”.

18.Press the [ÊÊÊÊÊEJECT]¤ button and remove the check disc (MD) TDYS-1.

6-4. Focus Bias Check

Change the focus bias and check the focus tolerance amount. Checking Procedure :

1.Load a test disk (MDW-74/AU-1).

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “CPLAY MODE” (C30).

3.Press the [YES] button twice and display “CPLAY MID”.

4.Press the [MENU/NO] button when “C = AD = ” is displayed.

5.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “FBIAS CHECK” (C05).

6.Press the [YES] button and display “ / c = ”.

The first four digits indicate the C1 error rate, the two digits after [/] indicate ADER, and the 2 digits after [c =] indicate the focus bias value.

Check that the C1 error is below 220 and ADER is below 2.

7.Press the [YES] button and display “ / b = ”. Check that the C1 error is below 220 and ADER is below 2.

8.Press the [YES] button and display “ / a = ”. Check that the C1 error is below 220 and ADER is below 2.

9.Press the [MENU/NO] button, next press the [ÊÊÊÊÊEJECT]¤ but- ton, and remove the test disc.

6-5. C PLAY Checking

MO Error Rate Check

Checking Procedure :

1.Load a test disk (MDW-74/AU-1).

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “CPLAY MODE” (C30).

3.Press the [YES] button and display “CPLAY MID”.

4.The display changes to “C = AD = ”.

5.If the C1 error rate is below 80, check that ADER is below 2.

6.Press the [MENU/NO] button, stop playback, press the [ÊÊÊÊÊEJECT]¤ button, and test disc.

CD Error Rate Check

Checking Procedure :

1.Load a check disc (MD) TDYS-1.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “CPLAY MODE” (C30).

3.Press the [YES] button twice and display “CPLAY MID”.

4.The display changes to “C = AD = ”.

5.Check that the C1 error rate is below 50.

6.Press the [MENU/NO] button, stop playback, press the [ÊÊÊÊÊEJECT]¤ button, and the test disc.

6-6. Self-Recording/playback Check

Prepare a continuous recording disc using the unit to be repaired and check the error rate.

Checking Procedure :

1.Insert a recordable disc (blank disc) into the unit.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “CREC MODE” (C31).

3.Press the [YES] button to display the “CREC MID”.

4.When recording starts, “ REC ” is displayed, this becomes “CREC @@@@” (@@@@ is the address), and recording starts.

5.About 1 minute later, press the [MENU/NO] button to stop continuous recording.

6.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “C PLAY MODE”(C30).

7.Press the [YES] button to display “C PLAY MID”.

8.“C = AD = ” will be displayed.

9.Check that the C1 error becomes below 80 and the AD error below 2.

10.Press the [MENU/NO] button to stop playback, and press the [ÊÊÊÊÊEJECT]¤ button and remove the disc.

– 26 –

Page 25 Page 27
Image 26
Page 25 Page 27
Contents MDM-5A SpecificationsMDS-JE520 SELF-DIAGNOSIS Function GeneralItems of Error History Mode Items and Contents Section Servicing Notes Table of ContentsDiagrams Varoitus Flexible Circuit Board RepairingVarning JIG for Checking BD Board Waveform IOPRecord Precedure REC/PLAY Checks Prior to Parts Replacement and AdjustmentsForced Reset Retry Cause Display Mode PrecedureHexadecimal nBinary Conversion Table Front view Rear view Section GeneralLocation of Controls Page Page Section Disassembly CaseFront Panel Seciton Main BoardMechanism Section MDM-5A Slider CAMBase Unit MBU-5A, BD Board SW BOARD, Loading Motor M103Setting the Test Mode Section Test ModePrecautions for USE of Test Mode Exiting the Test ModeSelecting the Test Mode Display Contents Mark GroupMID Operating the Continuous Playback ModeNon-Volatile Memory Mode EEP Mode Auto gain display Not used in servicing Test Mode DisplaysFunctions of Other Buttons Detrack check display Not used in servicingDisplay Contents When Lit When Off Meanings of Other DisplaysSection Electrical Adjustments Parts Replacement and AdjustmentPrecautions for Adjustments Precautions for Checking Laser Diode EmissinonPrecautions for USE of Optical PICK-UP KMS-260A Laser power meterCheck Prior to Repairs Temperature Compensation Offset CheckLaser Power Check Traverse CheckFocus Bias Check Play Checking MO Error Rate CheckCD Error Rate Check Self-Recording/playback CheckLaser Power Adjustment Initial Setting of Adjustment ValueTemperature Compensation Offset Adjutment Recording and Displaying the IOP InformationTraverse Adjustment Focus Bias Adjustment CD Auto Gain Control Output Level Adjustment Error Rate CheckAuto Gain Control Output Level Adjustment MO Auto Gain Control Output Level AdjustmentAdjusting Points and Connecting Points IC PIN Function Description Section DiagramsBD Board IC101 CXA2523AR RF AMP, FOCUS/TRACKING Error AMP Xrst SrdtSens SqsyMvci XrasXWE AsyoSprd SrdrSfdr SpfdMain Board IC100 CXD8607N A/D Converter TEST2 AvddlVDD1 LvddMain Board IC800 M30610MCA-264FP System Controller MDS-JB920 REC Analog Block Diagram Servo Section∙ Signal Path REC DigitalPlay Digital OUT Block Diagram Main Section∙ Signal Path Play Analog OUT Circuit Boards Location Printed Wiring Boards BD Section MDS-JB920 Schematic Diagram BD /2 See 53 for Waveforms. See page 70 and 71 for IC Block DiagramsWaveforms BD board Main board Disp board MDS-JB920 MDS-JB920 MDS-JB920 MDS-JB920 Other layers pattern Side a US, CND Schematic Diagram Panel Section See page 54 for Waveforms IC Block Diagrams BD Board IC101 Schematic Diagram BD Switch SectionPrinted Wiring Board BD Switch Section CXA2523ARIC121 CXD2654R IC152 BH6511FS-E2IC203 Main Board IC100 CXD8607NIC101 CXA8054M CXA8042ASIC200 CXD8767N SN74HC153ANS SN74HCU04ANS-E20Section Exploded Views Chassis SectionFront Panel Section Supplied with RV760209 4-988-466-21 Spring ELECTROSTATIC, Leaf 206 201204 205 Base Unit Section MBU-5A Section Electrical Parts List Diode F1J6TP TANTAL. ChipDiode CXA2523ARDisp Main C252 Mylar CXA8042AS HZS6C1LHZ7.5CP-TK SN74HC153ANS390 LED SEL6210S-TH10 Standby Main PSWCoil with Core Vibrator LED SEL6810A-TH10 Mega Control TransistorSW VOL Sony Corporation
Top Page Image Contents