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45

8. Press the

.  m

  “R”

or

M  >

  “R”

button so that the

waveform of the oscilloscope becomes the specified value.
(When the

.  m

 “R”

or

M  >

 “R”

button is pressed,

the 

 of “EFB= 

” changes and the waveform changes) In

this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.
(Write power traverse adjustment)

Traverse Waveform

9. Press the

ENTER/YES  “R”

button, and save the adjustment

results in the non-volatile memory. (“EFB = 

 SAVE” will be

displayed for a moment)

10. “EFB = 

 MO-P” will be displayed.

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

11. Press the

.  m

  “R”

or

M  >

  “R”

button until the

waveform of the oscilloscope moves closer to the specified
value.
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.

Traverse Waveform

12. Press the

ENTER/YES  “R”

button, and save the adjustment

results in the non-volatile memory. (“EFB = 

 SAVE” will be

displayed for a moment)
Next “EF MO ADJUST” (C07) is displayed. The disc stops
rotating automatically.

13. Press the 

[MD    ]

 button and take out the disc.

14. Load the check disc (TDYS-1).
15. Press the

. m

 “R”

or

M >

 “R”

button to display “EF

CD ADJUST” (C08).

16. Press the

ENTER/YES “R”

button to display “EFB = 

 CD”.

Servo is imposed automatically.

17. Press the

.  m

  “R”

or

M  >

  “R”

button so that the

waveform of the oscilloscope moves closer to the specified
value.
In this adjustment, waveform varies at intervals of approx. 2%.
Adjust the waveform so that the specified value is satisfied as
much as possible.

Traverse Waveform

18. Press the

ENTER/YES “R”

button, display “EFB = 

 SAVE”

for a moment and save the adjustment results in the non-volatile
memory.
Next “EF CD ADJUST” (C08) will be displayed.

19. Press the 

[MD    ]

 button and take out the  check disc.

Adjustment Location: BD (MD) board (see page 47)

Procedure:
1. Load the continuously-recorded disc.  (Refer to “5.  USING

THE CONTINUOUSLY RECORDED DISC” (See page 40))

2. Press the

.  m

  “R”

or

M  >

  “R”

button to display

“CPLAY2 MODE” (C36).

3. Press the

ENTER/YES “R”

button to display “CPLAY2MID”.

4. Press the

MENU/NO “R”

button when “C = 

 AD = 

)”

is displayed.

5. Press the

.  m

  “R”

or

M  >

  “R”

button to display

“FBIAS ADJUST” (C09).

6. Press the

ENTER/YES “R”

button to display “

/

 a = 

”.

The first four digits indicate the C1 error rate, the two digits
after “/ ” indicate ADER, and the 2 digits after “a =” indicate
the focus bias value.

7. Press the

M >

 “R”

button and find the focus bias value at

which the C1 error rate becomes about 200 (refer to Note 2).

8. Press the

ENTER/YES “R”

button to display “

/

 b = 

”.

9. Press the

. m

 “R”

button and find the focus bias value at

which the C1 error rate becomes about 200.

10. Press the

ENTER/YES “R”

button to display “

/

 c = 

”.

11. Check that the C1 error rate is below 20 and ADER is 00.

Then press the

ENTER/YES “R”

button.

12. If the “(

)” in “

 - 

 - 

  (

)” is above 20, press

the

ENTER/YES “R”

 button.

If below 20, press the

MENU/NO “R”

button and repeat the

adjustment from step 2.

13. Press the 

[MD    ]

 button and take out the disc.

The relation between the C1 error and focus bias is as shown in
the following figure. Find points A and B in the following figure
using the above adjustment. The focal point position C is auto-
matically calculated from points A and B.

As the C1 error rate changes, perform the adjustment using the
average vale.

Z

Z

Z

46

Procedure:
1. Load the check disc (TDYS-1).
2. Press the

.  m

  “R”

or

M  >

  “R”

button and display

“CPLAY2 MODE” (C36).

3. Press the

ENTER/YES “R”

button twice and display “CPLAY2

MID”.

4. The display changes to “C = 

 AD = 

)”.

5. Check that the C1 error rate is below 20.
6. Press the

MENU/NO “R”

button to stop playback, then press

the 

[MD    ]

 button and take out the check disc.

Procedure:
1. Load the continuously-recorded disc.  (Refer to “5.  USING

THE CONTINUOUSLY RECORDED DISC” (See page 40))

2. Press the

.  m

  “R”

or

M  >

  “R”

button to display

“CPLAY2 MODE” (C36).

3. Press the

ENTER/YES “R”

button to display “CPLAY2MID”.

4. The display changes to “C1 = 

 AD = 

)”.

5. If the C1 error rate is below 20, check that ADER is 00.
6. Press the

MENU/NO “R”

button to stop playback, then press

the   

[MD    ]

 button and take out the disc.

Change the focus bias and check the focus tolerance amount.

Procedure:
1. Load the continuously-recorded disc.  (Refer to “5.  USING

THE CONTINUOUSLY RECORDED DISC” (See page 40))

2. Press the

.  m

  “R”

or

M  >

  “R”

button to display

“CPLAY2 MODE” (C36).

3. Press the

ENTER/YES “R”

button twice to display “CPLAY2

MID”.

4. Press the

MENU/NO “R”

button when “C1 = 

 AD = 

)”

is displayed.

5. Press the

.  m

  “R”

or

M  >

  “R”

button to display

“FBIAS CHECK” (C16).

6. Press the

ENTER/YES “R”

button to display “

/

 c = 

”.

The first four digits indicate the C1 error rate, the two digits
after “/ ” indicate ADER, and the 2 digits after “c =” indicate
the focus bias value.
Check that the C1 error is below 20 and ADER is below 2.

7. Press the

ENTER/YES “R”

button and display “

/

 b =

”.

Check that the C1 error is below 100 and ADER is below 2.

8. Press the

ENTER/YES “R”

button and display “

/

 a =

”.

Check that the C1 error is below 100 and ADER is below 2

9. Press the

MENU/NO “R”

button, then press the 

[MD    ]

 button

and take out the disc.

If the C1 error and ADER are above other than the specified
value at points a (step 8. in the above) or b (step 7. in the above),
the focus bias adjustment may not have been carried out prop-
erly. Adjust perform the beginning again.

Be sure to perform this adjustment when the optical pick-up is
replaced.
If the adjustment results becomes “Adjust NG!”, the optical pick-
up may be faulty or the servo system circuits may be abnormal.

Procedure:
1. Load the check disc (TDYS-1).
2. Press the

. m

 “R”

or

M >

 “R”

button to display “AG

Set (CD)” (C11).

3. When the

ENTER/YES “R”

button is pressed, the adjustment

will be performed automatically.
“Complete!” will then be displayed momentarily when the
value is recorded in the non-volatile memory, after which the
display changes to “AG Set (CD)” (C11).

4. Press the 

[MD    ]

 button and take out the check disc.

Procedure:
1. Load the test disc (MDW-74/GA-1).
2. Press the

. m

 “R”

or

M >

 “R”

button to display “AG

Set (MO)” (C10).

3. When the

ENTER/YES “R”

button is pressed, the adjustment

will be performed automatically.
“Complete!” will then be displayed momentarily when the
value is recorded in the non-volatile memory, after which the
display changes to “AG Set (MO)” (C10).

4. Press the 

[MD    ]

 button and take out the test disc.

Z

Z

Z

Z

Z

47

It is useful to use the jig for checking the waveform. (Refer to Ser-
vicing Notes on page 11)

48

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.

5. Level doesn’t change whichever with normal speed or with four times

speed.

6. Use the following jig.

• Extension jig (21 core) (Part No. J-2501-075-A)

CN101 on the BD (CD) board to CN1002 on the MD DIGITAL board

Procedure:
1. Connect an oscilloscope to test point TP (FE) and TP (VC) on

the BD (CD) board.

2. Turn the power on.
3. Put the disc (YEDS-18) in and turned power switch on again

and actuate the focus search. (actuate the focus search when disc
table is moving in and out)

4. Check the oscilloscope waveform (S-curve) is symmetrical

between A and B. And confirm peak to peak level within 3.6 ±
0.5 Vp-p.

S-curve waveform

 • Try to measure several times to make sure than the ratio of A : B

or B : A is more than 10 : 7.

• Take sweep time as long as possible and light up the

brightness to obtain best waveform.

Checking Location: BD (CD) board

Procedure:
1. Connect an oscilloscope to test point TP (RF) and TP (VC) 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

Procedure:
1. Connect an oscilloscpe to test point TP (TE) and TP (VC) on the

BD (CD) board.

2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Press the 

[REPEAT]

 button.  (The tracking servo and the sled-

ding servo are turned OFF)

5. Check the level B of the oscilliscope's waveform and the A (DC

voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ± 22%

Traverse Waveform

6. Press the 

[REPEAT]

 button. (The tracking servo and sledding

servo are turned ON)
Confirm the C (DC voltage) is almost equal to the A (DC volt-
age) is step 5.

Traverse Waveform

Checking Location: BD (CD) board

±

±