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33

1. CD Block is basically designed to operate without adjustment. There-

fore, check each item in order given.

2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M

Ω

 impedance.

4. Clean the object lens by an applicator with neutral detergent when the

signal level is low than specified value with the following checks.

As the laser diode in the optical pick-up (OPTIMA-720L1E) is easily
damaged by static electricity, solder the laser tap of the flexible
board when handling it. Before disconnecting the connector, solder
first. Before connecting 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.

Procedure:
1. Connect an oscilloscope to test point TP (RFAC) and TP (DVC

1.65V) on the BD (CD) board.

2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RF sig-

nal level is correct or not.

A clear RF signal waveform means that the shape “

◊

” can be clearly

distinguished at the center of the waveform.

                    RF signal waveform

Checking Location: BD (CD) board

+

–

BD (CD) board

TP (RFAC)

TP (DVC 1.65V)

oscilloscope

(AC range)

VOLT/DIV: 200 mV

TIME/DIV: 500 ns

level: 1.1 

±

0.3 Vp-p

pick-up

frexible board

laser tap

– BD (CD) BOARD –

TP 

(RFAC)

TP

(DVC 1.65V)

IC103

IC101

34

Other faults are suspected.
Check the mechanism parts (spindle motor, sled motor, etc.).

Start

NG

NG

NG

OK

OK

OK

Laser Power Check

6-2.

(See page 37)

6-3.

(See page 37)

6-4.

(See page 38)

Iop Compare

Auto Check

Replace optical pick-up or MDM-7B4B

About “R”
As this unit has only a few buttons, some operations require the use of remote commander (RM-SC5BEN/provided with unit: 1-476-649-11)
buttons. These operations are indicated as “R” in this manual.
Example:  

MENU/NO “R”

  ...Press the  

MENU/NO

  button of the remote commander.

Incorrect operations may be performed if the MD test mode is not entered properly.
In this case, press the  

?/1

  button to turn the power off, and retry to enter the MD test mode.

If malfunctions caused by optical pick-up such as sound skipping are suspected, follow the following check.

35

6-4. Auto Check
(See page 38)

YES

NO

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

Replace IC195

Replace OP or IC195

Replace IC101, IC195, or D101

11. Iop NV SAVE (See page 41)

Replace OP, IC190, or IC195

Replace OP, IC102, IC190, 

or IC195

Replace OP, IC101, IC151, 

or IC195

Replace OP

After turning off and then on the power, 
initialize the EEPROM
For details, refer to “WHEN MEMORY NG IS DIS- 
PLAYED” in Section 4. TEST MODE (See page 29)

• Abbreviation

OP: optical pick-up

7. INITIAL SETTING OF ADJUSTMENT VALUE 

(See page 40)

9. TEMPERATURE COMPENSATION OFFSET 

ADJUSTMENT (See page 40)

10. LASER POWER ADJUSTMENT (See page 40)

12. TRAVERSE ADJUSTMENT (See page 41)
13. FOCUS BIAS ADJUSTMENT (See page 43)
16. AUTO GAIN CONTROL OUTPUT LEVEL

ADJUSTMENT (See page 44)

8. RECORDING AND DISPLAYING THE IOP 

INFORMATION  (See page 40)

End adjustments

Start

36

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 handling
it.
Before disconnecting the connector, solder first. Before connecting
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.

pick-up

flexible board

laser tap

1. When replacing the following parts, perform the adjustments

and checks with 

 in the order shown in the following table.

2. Set the MD test mode when performing adjustments.

After completing the adjustments, exit the MD test mode.
Perform the adjustments and checks in “Group Service” of the
MD test mode.

3. Perform the adjustments to be needed in the order shown.
4. Use the following tools and measuring devices.

• Check Disc (TDYS-1) (Part No. : 4-963-646-01)
• Test Disk (MDW-74/GA-1) (Part No. : 4-229-747-01)
• Laser power meter LPM-8001 (Part No. : J-2501-046-A)

or MD Laser power meter 8010S (Part No. : J-2501-145-A)*

1

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

(Part No. : J-2501-196-A)

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

make sure that VC and ground do not connect inside the
oscilloscope.
(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 Notes on page 6.)

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

that no dusts nor fingerprints are attached to it.

*

1

When performing laser power checks and adjustment (electrical
adjustment), use of the new MD laser power meter 8010S (Part
No. J-2501-145-A) instead of the conventional laser power
meter is convenient.
It sharply reduces the time and trouble to set the laser power
meter sensor onto the objective lens of optical pick-up.

7.

Initial setting of adjustment value

8.

Recording of Iop information

9.

Temperature compensation

offset adjustment

10. Laser power adjustment

11. Iop NV Save

12. Traverse adjustment

13. Focus bias adjustment

16. Auto gain control output level

adjustment

6-4. AUTO CHECK