Sony MDS-JE630 Check Prior To Repairs, Temperature Compensation Offset Check, Checking Procedure

+

–

oscilloscope (DC range)

6. CHECK 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 8).

6-1. Temperature Compensation Offset Check

When performing adjustments, set the internal temperature and room temperature of 22 °C to 28 °C.

Checking Procedure:

1.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “TEMP CHECK” (C01).

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)

6-2. Laser Power Check

Before checking, check the IOP value of the optical pick-up. (Refer to 8. Recording and Displaying the IOP Information)

Connection :

laser

power meter

Optical pick-up objective lens

digital voltmeter

BD board
CN110 pin 5	(I +3V)
		+
CN110 pin 4	(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 [ÊÊÊÊÊÊ]0 but- ton or[ÊÊÊÊÊÊ]) button to move the optical pick-up)

Connect the digital voltmeter to CN110 pin 5 (I+3V) and CN110 pin 4 (IOP) on the BD board.

2.Then, turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “LDPWR CHECK” (C02).

3.Press the [YES] button once to display “LD 0.9 mW $ ”. Check that the reading of the laser power meter become 0.84 to 0.92 mW.

4.Press the [YES] button once more to display “LD 7.0 mW $

”. Check that the reading the laser power meter and digital voltmeter satisfy the specified value.

Specified Value:

Laser power meter reading : 7.0 ± 0.2 mW

Digital voltmeter reading : Value on the optical pick-up label ±10%

(Optical pick-up label)

KMS260A

27X40 B0825

lOP=82.5 mA in this case

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

5.Press the [MENU/NO] button to 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 “LD 0.7 mW $		”, “LD 6.2 mW $	”, and
“LD Wp	$ ”. Nothing needs to be performed here.

6-3. Traverse Check

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

330 k Ω

CN110 pin 3 (TEO)

CN110 pin 1 (VC) 10 pF

Connection :

oscilloscope (DC range)

BD board

CN110 pin 3	(TEO)	+		V: 0.1 V/div
CN110 pin 1	(VC)
			–	H: 10 ms/div

Checking Procedure:

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

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

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

4.Turn the [ÊÊÊÊÊÊÊÊAMSÊÊÊÊÊÊÊÊ]- ± knob to display “EF MO CHECK” (C03).

5.Press the [YES] button to display “EFB = MO-R”.

(Laser power READ power/Focus servo ON/tracking servo OFF/spindle (S) servo ON)

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

(Read power traverse checking)

Traverse Waveform

A

VC

B

Specified value : Below 10% offset value

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

7.Press the [YES] button to display “EFB = MO-W”.

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

(Write power traverse checking)

Traverse Waveform

A

VC

B

Specified value : Below 10% offset value

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

– 24 –