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21

Contents

Sets continuous playback state.

playback, the tracking servo turns ON.

Stops continuous playback and continuous recording.

The sled moves to the outer circumference only when this is pressed.

The sled moves to the inner circumference only when this is pressed.

ON/OFF of recording head arm each time the button is pressed.

Ejects the disc

Function

H

x

M

m

zREC

A

22

• Check and adjust the MDM and MBU as follows.

The procedure changes according to the part replaced

• Abbreviation

OP

: Optical pick-up

OWH: Overwrite head

• Temperature compensation offset check 
   (5-6-1)
• Laser power check (5-6-2)
• Traverse check (5-6-3)
• Focus bias check (5-6-4)
• C PLAY check (5-6-5)
• Self-recording/playback check (5-6-6)

Parts Replacement and Repair

NG

Has the OWH been replaced?

NO

OK

NO

NO

NO

Has OP, IC171, IC101, or 
IC121 been replaced?

YES

YES

Initial setting of the adjustment value

Has OP or IC171 been replaced?

YES

IOP information recording
(IOP value labeled on OP)

Has IC171 or D101 
been replaced?

YES

Temperature compensation offset adjustment

• Laser power adjustment (5-10)
• Traverse adjustment (5-11)
• Focus bias adjustment (5-12)
• Error rate check (5-13)
• Focus bias check (5-14)
• Auto gain adjustment (5-15)

Check the sleding and spindle 
mechanisms. 
Other causes can be suspected.

23

To check the emission of the laser diode during adjustments, never
view directly from the top as this may lose your eye-sight.

As the laser diode in the optical pick-up is easily damaged by static
electricity, solder the laser tap of the flexible board when using it.
Before disconnecting the connector, desolder first. Before connect-
ing the connector, be careful not to remove the solder. Also take
adequate measures to prevent damage by static electricity. Handle
the flexible board with care as it breaks easily.

1) When replacing the following parts, perform the adjustments

and checks with      in the order shown in the following table.

Optical

Pick-up

BD Board

IC101, IC121

D101

IC171

1. Initial setting of

adjustment value

2. Recording of IOP

information
(Value written in
the pick-up)

3. Temperature

compensation
offset adjustment

4. Laser power

adjustment

5. Traverse

adjustment

6. Focus bias

adjustment

7. Error rate check

8. Auto gain output

level adjustment

IC192

2) Set the test mode when performing adjustments.

After completing the adjustments, exit the test mode.
Perform the adjustments and checks in “group S” of the test mode.

3) Perform the adjustments to be needed in the order shown.

4) Use the following tools and measuring devices.

• Check Disc (MD) TDYS-1

(Parts No. 4-963-646-01)

• Test Disk (MDW-74/AGA-1) (Parts No. 4-229-747-01)
• Laser power meter LPM-8001 (Parts No. J-2501-046-A)
or

MD Laser power meter 8010S (Parts No. J-2501-145-A)

• Oscilloscope (Measure after performing CAL of prove.)
• Digital voltmeter
• Thermometer
• Jig for checking BD board waveform

(Parts No. : J-2501-149-A)

5) When observing several signals on the oscilloscope, etc.,

make sure that VC and ground do not connect inside the oscillo-
scope.
(VC and ground will become short-circuited.)

6) Using the above jig enables the waveform to be checked without

the need to solder.
(Refer to Servicing Note on page 6.)

7) As the disc used will affect the adjustment results, make sure

that no dusts nor fingerprints are attached to it.

* 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 L  knob and display “MD CREC MODE”.
3. Press the  ENTER/YES  button again to display “MD CREC

MID”. Display “MD CREC (0300)” and start to recording.

4. Complete recording within 5 minutes.
5. Press the  MENU/NO  button and stop recording .
6. Press the  A  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.

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
Adjustments” (See page 9).

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

Checking Procedure:
1. Rotate the  l L  knob to display “MD TEMP CHECK”.
2. Press the  ENTER/YES  button.
3. “MD T=@@(##) [OK]” should be displayed. If “MD 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 5-8. Recording and Displaying the IOP Information.)

KMS

260A

27X40
B0825

T

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

Ω

)

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 CN110 pin 5 (I+3V) and
CN110 pin 4 (IOP).

2. Then, rotate the  l L  knob and display “MD LDPWR

CHECK”.

3. Press the  ENTER/YES  button once and display “MD 0.9 mW

*** $  ”. Check that the reading of the laser power meter
become 0.84 to 0.92 mW. (

*** means IOP value)

4. Press the  ENTER/YES  button once more and display “MD 7.0

mW 

*** $  ”. Check that the reading the laser power meter

and digital volt meter satisfy the specified value.

Laser power meter reading : 7.0 ± 0.2 mW
Digital voltmeter reading : Optical pick-up displayed value ± 10%

(Optical pick-up label)

5. Press the  MENU/NO  button and display “MD LDPWR

CHECK” and stop the laser emission.
(The  MENU/NO  button is effective at all times to stop the laser
emission.)

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

Checking 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  m  button and move the optical pick-up outside the

pit.

4. Rotate the  l L  knob and display “MD EF MO CHECK”.
5. Press the  ENTER/YES  button and display “MD 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 rotate the  l L  knob.
(Read power traverse checking)

(Traverse Waveform)

7. Press the  ENTER/YES  button and display “MD EFB = 

MO-W”.

8. Observe the waveform of the oscilloscope, and check that the

specified value is satisfied. Do not rotate the  l L  knob.
(Write power traverse checking)

(Traverse Waveform)

9. Press the  ENTER/YES  button display “MD EFB = 

 MO-P”.

Then, the optical pick-up moves to the pit area automatically
and servo is imposed.

Note 1: After step 4, each time the  ENTER/YES  button is pressed,

the display will be switched between “MD LD 0.7 mW $

”,  “MD LD 0.7 mW $ 

”,  “MD LD 6.2 mW $ 

”,

“MD  LD WP                        $ 

”,  “MD LD 0.9 mW $ 

”.

Nothing needs to be performed here.

5

4

3

1

IA – BI

IA – BI