Sony MDS-JB920 service manual Traverse Adjustment, Specification, Connection, Adjusting Procedure

Models: MDS-JB920

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11. TRAVERSE ADJUSTMENT
+
oscilloscope (DC range)

7.Then, rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “LDPWR CHECK” (C02).

8.Press the [YES] button once and display “LD 0.9 mW $ – 28 –Manual background ”. Check that the reading of the laser power meter become 0.85 to 0.91 mW.

9.Press the [YES] button once more and display “LD 7.0 mW $

Manual backgroundManual background ”. Check that the reading the laser power meter and digital volt meter satisfy the specified value.

Note down the digital voltmeter reading value.

Specification:

Laser power meter reading: 7.0 ± 0.2 mW

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

(Optical pick-up label)

KMS260A

27X40 B0567

lOP=56.7 mA in this case

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

10.Press the [MENU/NO] button and display “LDPWR CHECK” and stop the laser emission.

(The [MENU/NO] button is effective at all times to stop the laser emission.)

11.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “Iop.Write”(C28).

12.Press the [YES] button. When the display becomes Ref=@@@.@ (@ is an arbitrary number), press the [YES] button to display “Measu=@@@.@” (@ is an arbitrary num- ber).

13.The numbers which can be changed will blink. Input the Iop value noted down at step 9.

To select the number : Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob.

To select the digit : Press the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob.

14.When the [YES] button is pressed, “Complete!” will be dis- played momentarily. The value will be recorded in the non- volatile memory and the display will become “Iop Write”.

Note 1: After step 4, each time the [YES] button is pressed, the display

will be switched between “LD 0.7 mW $ Manual backgroundManual backgroundManual backgroundManual background ”, “LD 6.2 mW $

Manual backgroundManual background ”, and “LD Wp Manual backgroundManual backgroundManual backgroundManual background$ Manual backgroundManual backgroundManual backgroundManual background ”. Nothing needs to be performed here.

11. TRAVERSE ADJUSTMENT

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

Note 2: If the traverse waveform is not clear, connect the oscilloscope as shown in the following figure so that it can be seen more clearly.

BD board

Manual background 330 k Ω

CN110 pin 3 (TE)

CN110 pin 1 (VC) Manual background 10 pF

Connection :

oscilloscope (DC range)

BD board

 

 

CN110 pin 3

(TE)

+

V: 0.1 V/div

CN110 pin 1

(VC)

H: 10 ms/div

 

 

 

Adjusting Procedure :

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

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

3.Press the [ÊÊÊÊÊÊ]) button and move the optical pick-up outside the pit.

4.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob and display “EF MO ADJUS” (C10).

5.Press the [YES] button and display “EFB = Manual backgroundManual background MO-R”. (Laser power READ power/Focus servo ON/tracking servo OFF/spindle (S) servo ON)

6.Rotate the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob so that the waveform of the oscilloscope becomes the specified value.

(When the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob is rotated, the Manual backgroundManual background of “EFB=

Manual backgroundManual background” changes and the waveform changes.) In this adjustment, waveform varies at intervals of approx. 2%. Adjust the wave- form so that the specified value is satisfied as much as pos- sible.

(Read power traverse adjustment)

(Traverse Waveform)

A

VC

B

Specification A = B

7.Press the [YES] button and save the result of adjustment to

the non-volatile memory (“EFB = Manual backgroundManual background SAV” will be displayed

for a moment. Then “EFB = Manual backgroundManual background MO-W” will be displayed).

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Sony MDS-JB920 service manual Traverse Adjustment, Specification, Connection, Adjusting Procedure