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37

Procedure:
1. Connect the frequency counter to check point of the VIDEO

board.

2. Turned  ?/1  button switch on.
3. Press the  FUNCTION  button to select the CD.
4. Adjust CT503 on the VIDEO board so that the frequency counter

reading 27.0 MHz 

±

 80 Hz at stop status.

[VIDEO BOARD] (SIDE A)

38

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

Other faults are suspected.
Check the threading mechanism, etc.

Start

NG

NG

NG

OK

OK

OK

Laser Power Check

6-6-2.

(See page 41)

6-6-3.

(See page 41)

6-6-4.

(See page 42)

Iop Compare

Auto Check

Replace Optical pick-up or MDM-7B

39

6-6-4. Auto Check
(See page 42)

Start

YES

NO

NO

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

YES

Replace IC195

Replace OP or IC195

Replace IC101, IC195, or D101

6-11. Iop NV SAVE (See page 45)

Replace OP, IC190, or IC195

Replace OP, IC102, IC190, 

or IC195

Replace OP, IC101, IC151, 

or IC195

Replace OP

Replace the spindle motor

End adjustments

After turning off and then on the power, 
initialize the EEPROM
For details, refer to 4-11. WHEN MEMORY NG IS 
DISPLAYED (See page 32)

• Abbreviation

OP: Optical pick-up

6-7. INITIAL SETTING OF ADJUSTMENT VALUE 

(See page 44)

6-9. TEMPERATURE COMPENSATION OFFSET 

ADJUSTMENT (See page 44)

6-10. LASER POWER ADJUSTMENT (See page 44)

6-12. TRAVERSE ADJUSTMENT (See page 45)
6-13. FOCUS BIAS ADJUSTMENT (See page 46)
6-16. AUTO GAIN CONTROL OUTPUT LEVEL

ADJUSTMENT (See page 47)

OP change in Err Display mode
Iop write

Spindle change in Err Display mode

40

Parts to be replaced

6-7. Initial setting of adjustment values

6-8. Recording and displaying the Iop information

6-9. Temperature compensation offset adjustment

6-10. Laser power adjustment

6-11. Iop NV Save

6-12. Traverse adjustment

6-13. Focus bias adjustment

6-16. Auto gain control output level adjustment

6-6-4. Auto Check

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.

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/GA-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 (MD) board waveform

(Parts No. : J-2501-196-A)

Optical

Pick-up

IC101

IC102

IC151

IC190

IC195

D101

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 9.)

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

that no dusts nor fingerprints are attached to it.

Adjustment