Sony MDS-PC3 specifications Focus Bias Adjustment

Page 32

10.Rotate the AMS knob until the waveform of the oscilloscope moves closer to the specified value.

In this adjustment, waveform varies at intervals of approx. 2%. Adjust the waveform so that the specified value is satisfied as much as possible.

(Traverse Waveform)

A

VC

B

Specification A = B

11.Press the @/1 button, and save the adjustment results in the non-volatile memory. (“EFB = SAVE” will be displayed for a moment.)

Next “EF MO ADJUS (C07)” is displayed. The disc stops ro- tating automatically.

12.Press the x/Z “PGM” button and remove the disc.

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

14.Roteto AMS knob and display “EF CD ADJUS” (C08).

15. Press the @/1 button and display “EFB = CD”. Servo is imposed automatically.

16.Rotate the AMS knob so that the waveform of the oscilloscope moves closer to the specified value.

In this adjustment, waveform varies at intervals of approx. 2%. Adjust the waveform so that the specified value is satisfied as much as possible.

(Traverse Waveform)

A

VC

B

Specification A = B

17. Press the @/1 button, display “EFB = SAVE” for a mo- ment and save the adjustment results in the non-volatile memory. Next “EF CD ADJUST” (C08) will be displayed.

18.Press the x/Z “PGM” button and remove the check disc (MD) TDYS-1.

Note 1 : MO reading data will be erased during if a recorded disc is used in this adjustment.

Note 2 : If the traverse waveform is not clear, connect the oscillo- scope as shown in the following figure so that it can be

seen more clearly.

Oscilloscope

BD board

330 kΩ

CN105 pin 4 (TE)

10pF

CN105 pin 6

(VC)

 

5-13. FOCUS BIAS ADJUSTMENT

Adjusting Procedure :

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

2.Rotate the AMS knob and display “CPLAY1MODE” (C34).

3.Press the @/1 button and display “CPLAY1 MID”.

4. Press the

x/Z

button when “C =

AD = )” is dis-

played.

 

5.Rotate the AMS knob and display “FBIAS ADJUST” (C09).

6.Press the @/1 button and display “ / a = T)”.

The first four digits indicate the C error rate, the two digits after

[/]indicate ADER, and the 2 digits after [a =] indicate the focus bias value.

7.Rotate the AMS knob in the clockwise direction and find the focus bias value at which the C error rate becomes 200 (Refer to Note 2).

8.Press the @/1 button and display “ / b = T”.

9.Rotate the AMS knob in the counterclockwise direction and find the focus bias value at which the C error rate becomes 200.

10.Press the @/1 button and display “ / c = T)”.

11.Check that the C error rate is below 20 and ADER is 00. Then

 

press the

@/1

button.

 

 

 

 

12.

If the “(

” in “ - -

 

( ” is above 20, press the

@/1

 

button.

 

 

 

 

 

 

 

 

If below 20, press the

 

x/Z

button and repeat the

 

adjustment from step 2.

 

 

 

 

13.

Press the

x/Z “PGM”

 

button to remove the test disc.

Note 1 : The relation between the C error and focus bias is as shown in the following figure. Find points a and b in the following figure using the above adjustment. The focal point position c is automatically calculated from points a and b.

Note 2 : As the C error rate changes, perform the adjustment using the average vale.

Cerror

200

b

c

a

Focus bias value

 

 

 

(F. BIAS)

32

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Contents Specifications MDS-PC3SELF-DIAGNOSIS Function TOC t Edit t TOC Edit t blank tItems of Error History Mode Items and Contents Table of Contents DisassemblyDiagrams Table of Error CodesLead free soldering Section Service NotesFlexible Circuit Board Repairing JIG for Checking BD Board Waveform Record Precedure Main Board Component Side Checks Prior to Parts Replacement and AdjustmentsForced Reset Retry Cause Display Mode Bit BinaryHexadecimal t Binary Conversion Table Remote Parts Description General SectionUsing the Display Hooking Up Section Disassembly MD Mechanism Deck MDM-7AMain Board Over Light Head HR901, BD MD BoardHolder Assy Loading Motor Assy M103Sled Motor Assy M102, Slider Optical PICK-UP MD KMS-260B/JINSpindle Motor Assy M101 Section Test Mode Precautions for USE of Test ModeSetting the Test Mode Exiting the Test ModeSelecting the Test Mode Display Details Mark GroupOperating the Continuous Playback Mode Test Mode Displays Mode displayError rate display Functions of Other ButtonsInformation Meanings of Other DisplaysAutomatic SELF-DIAGNOSIS Function Check before replacement 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 Using the Continuously Recorded Disc Checks Prior to RepairsAuto Check Other ChecksPlay Check MO Error Rate Check CD Error Rate CheckLaser Power Adjustment Initial Setting of Adjustment ValueTemperature Compensation Offset Adjutment Traverse Adjustment Iop NV SaveFocus Bias Adjustment Error Rate Check Auto Gain Control Output Level AdjustmentCD Auto Gain Control Output Level Adjustment MO Auto Gain Control Output Level AdjustmentAdjusting Points and Connecting Points Diagrams Block Diagrams BD Section MDS-PC3Main Section Sclk CclkPrinted Wiring Board BD Section SemiconductorPIN Function MDS-PC3 Printed Wiring Board Main Section PIN Functon MDS-PC3 Printed Wiring Board Panel Section Schematic Diagram Panel Section See page 35 for Waveforms IC Block Diagrams IC101 CXA2523AR BD BoardLB1830M-S-TE-L Main Board BH3541F-E2 Main Board IC PIN Functions IC101 CXA2523AR RF Amplifier BD BoardMNT0 FOK Mvci IC300 M30805SGP Main Board Shck MNT1 Section Exploded Views Chassis SectionMechanism MDM-7A 319 302 320 317 304 308 303 305 306 301 318 307Mechanism 351Section Electrical Parts List Remarks Ref. No DescriptionMetal Chip Main PIN, Connector 2P Diode Main Panel MDS-PC3 Panel KEY REFLECT/PROTECT SW
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