Sony MDS-JB920 Error Rate Check, Focus Bias Check, Auto Gain Control Output Level Adjustment

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13.ERROR RATE CHECK

13-1. 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 20.

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

13-2. MO Error Rate Check

Checking Procedure :

1.Load a test disc (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 “C1 = AD = ”.

5.If the C1 error rate is below 50, check that ADER is 00.

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

14. FOCUS BIAS CHECK

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

1.Load a test disc (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 50 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 continuously recorded disc.

Note 1: If the C1 error and ADER are above other than the specified value at points a (step 8. in the above) or b (step 7. in the above), the focus bias adjustment may not have been carried out prop- erly. Adjust perform the beginning again.

15.AUTO GAIN CONTROL OUTPUT LEVEL ADJUSTMENT

Be sure to perform this adjustment when the pickup is replaced. If the adjustment results becomes “Adjust NG!”, the pickup may be faulty or the servo system circuits may be abnormal.

15-1. CD Auto Gain Control Output Level Adjustment

Adjusting Procedure :

1.Insert the check disc (MD) TDYS-1.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “AG Set (CD)” (C26).

3.When the [YES] button is pressed, the adjustment will be per- formed automatically.

“Complete!!” will then be displayed momentarily when the value is recorded in the non-volatile memory, after which the display changes to “AG Set (CD)”.

4.Press the [ÊÊÊÊÊEJECT]¤ button to remove the disc.

15-2. MO Auto Gain Control Output Level Adjustment

Adjusting Procedure :

1.Insert the reference disc (MDW-74/AU-1) for recording.

2.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “AG Set (MO)” (C25).

3.When the [YES] button is pressed, the adjustment will be per- formed automatically.

“Complete!!” will then be displayed momentarily when the value is recorded in the non-volatile memory, after which the display changes to “AG Set (MO)”.

4.Press the [ÊÊÊÊÊEJECT]¤ button to remove the disc.

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Contents Specifications MDS-JE520MDM-5A SELF-DIAGNOSIS Function GeneralItems of Error History Mode Items and Contents Table of Contents DiagramsSection Servicing Notes Flexible Circuit Board Repairing VarningVaroitus JIG for Checking BD Board Waveform IOPRecord Precedure Checks Prior to Parts Replacement and Adjustments Forced ResetREC/PLAY Retry Cause Display Mode PrecedureHexadecimal nBinary Conversion Table Section General Location of ControlsFront view Rear view 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 GroupOperating the Continuous Playback Mode Non-Volatile Memory Mode EEP ModeMID 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 Section Diagrams BD Board IC101 CXA2523AR RF AMP, FOCUS/TRACKING Error AMPIC PIN Function Description 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 DigitalBlock Diagram Main Section ∙ Signal Path Play Analog OUTPlay Digital 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 RV760206 201 204 205209 4-988-466-21 Spring ELECTROSTATIC, Leaf 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
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