Sony MDS-JE770 specifications Using the Continuously Recorded Disc, Checks Prior to Repairs

MDS-JE770

5-5. USING THE CONTINUOUSLY RECORDED DISC

*This disc is used in focus bias adjustment and error rate check. The following describes how to create a continuous recording disc.

1.Insert a disc (blank disc) commercially available.

2.Rotate the l AMS L knob and display “CREC1 MODE”(C35).

3.Press the YES button again to display “CREC1 MID”. Display “CREC (0300)” and start to recording.

4.Complete recording within 5 minutes.

5.Press the MENU/NO button and stop recording .

6.Press the AEJECT button and remove the disc.

The above has been how to create a continuous recorded data for the focus bias adjustment and error rate check.

Note :

• Be careful not to apply vibration during continuous recording.

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 Adjust- ments” (See page 9).

5-6-1. Temperature Compensation Offset Check

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

Checks cannot be performed properly if performed after some time from power ON due to the rise in the temperature of the IC and diode, etc. So, perform the checks again after waiting some time.

Checking Procedure:

1.Rotate the lAMS L knob to display “TEMP CHECK”. (C12)

2.Press the YES 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.)

Connection :

Laser power meter

Optical pick-up objective lens

Digital volt meter

BD board

CN105 pin 1 (I+3V)

CN105 pin 2 (IOP)

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 m button or M button to move the optical pick-up.)

Connect the digital volt meter to CN105 pin 1 (I+3V) and CN105 pin 2 (IOP).

2.Then, rotate the lAMS L knob and display “LDPWR CHECK”.

3. Press the YES button once and display “LD 0.9 mW $ ”. Check that the reading of the laser power meter become the specified value.

4.Press the YES 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 : LD 0.9mW : 0.85-0.91mW (260B) 0.90-0.96mW (260E)

LD 7.0mW : 6.80-7.20mW (260B) 7.00-7.50mW (260E)

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

(Optical pick-up label)

KMS260B	(For details of the method for checking
20101	this value, refer to “5-8. Recording and
H0576	Displaying Iop Information”.)

R

Iop = 57.6 mA in this case

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

5.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.)

Note 1: After step 4, each time the YES 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. Iop Compare

The current Iop value at laser power 7 mw output and reference Iop value (set at shipment) written in the nonvolatile memory are compared, and the rate of increase/decrease will be displayed in percentage.

Note: Perform this function with the optical pick-up set at room temperature.

Procedure

1.Rotate the l AMS L knob to display “Iop Compare”(C27).

2.Press the YES button and start measurements.

3.When measurements complete, the display changes to “±xx%yy”.

xx is the percentage of increase/decrease, and OK or NG is displayed at yy to indicate whether the percentage of increase/ decrease is within the allowable range.

4.Press the MENU/NO button to end.

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