Sony mds-jb730 User Manual

– 24 –

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).

When performing adjustments, set the internal temperature and
room temperature of 22 

°

C to 28 

°

C.

Checking Procedure:
1. Turn the 

[        AMS        ]

 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)

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

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

0  but-

ton or

) 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 

[        AMS        ]

 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%

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)

±

≠

Optical pick-up
objective lens

laser
power meter

+
–

BD board

digital voltmeter

CN110 pin 

5

 (I +3V)

CN110 pin 

4

 (IOP)

[      ]

[      ]

±

≠

KMS260A

27X40
B0825

lOP=82.5 mA in this case
lOP (mA) = Digital voltmeter reading (mV)/1 (

Ω

)

(Optical pick-up label)

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.

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

) button to move the optical pick-up outside the

pit.

4. Turn the 

[          AMS          ]

 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

[        AMS        ]

knob.
(Read power traverse checking)

Traverse Waveform

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 

[        AMS        ]

knob.
(Write power traverse checking)

Traverse Waveform

+
–

oscilloscope

(DC range)

V: 0.1 V/div
H: 10 ms/div

BD board

CN110 pin 

3

 (TEO)

CN110 pin 

1

 (VC)

[      ]

±

≠

±

≠

A

B

VC

Specified value : Below 10% offset value

Offset value (%) =                  X 100  

I

A – B I

2 (A + B)

A

B

VC

Specified value : Below 10% offset value

Offset value (%) =                  X 100  

I

A – B I

2 (A + B)

±

≠

+
–

oscilloscope

(DC range)

10 pF

330 k 

Ω

CN110 pin 

3

 (TEO)

CN110 pin 

1

 (VC)

BD board

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

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