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– 37 –

8. Turn the

≠

↔

± dial so that the waveform of the oscil-

loscope becomes the specified value.
(When the

≠

↔

± dial is turned, the   of “EFB-  ”

changes and the waveform transforms)
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]

button, and save the adjustment re-

sults 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. Turn the

≠

↔

± dial until the waveform of the oscillo-

scope becomes 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]

button, and save the adjustment re-

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

 SAVE” will be

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

13. Press the

§ (MD) button and take out the disc.

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

≠

↔

± dial to display “EF CD ADJUST”

(C12).

16. Press the

[ENTER/YES]

button to display “EFB = 

 CD”.

Servo is imposed automatically.

17. Turn the

≠

↔

± dial so that the waveform of the oscil-

loscope becomes 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]

button, display “EFB = 

 SAVE”

for a moment and save the adjustment results in the non-vola-
tile memory.
Next “EF CD ADJUST” will be displayed.

19. Press the

§ (MD) button and take out the check disc (MD)

TDYS-1.

Adjusting Procedure :
1. Load a test disk (MDW-74/AU-1).
2. Turn the

≠

↔

± dial to display “CPLAY MODE” (C30).

3. Press the

[ENTER/YES]

button to display “CPLAY MID”.

4. Press the 

[MENU/NO]

  button when “C = 

 AD = 

” is

displayed.

5. Turn the

≠

↔

± dial to display “FBIAS ADJUST”

(C13).

6. Press the

[ENTER/YES]

button to  display “

/

 a = 

”.

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

7. Turn the

≠

↔

± dial in the clockwise and find the fo-

cus bias value at which the C1 error rate becomes 220. (Refer
to Note 2)

8. Press the

[ENTER/YES]

button and display “

/

 b = 

”.

9. Turn the

≠

↔

± dial in the counterclockwise and find

the focus bias value at which the C1 error rate becomes 220.

10. Press the

[ENTER/YES]

button to display “

/

 c = 

”.

11. Check that the C1 error rate is below 50 and ADER is 00.

Then press the

[ENTER/YES]

button.

12. If the “(

” in “

 - 

 - 

 (

” is above 20, press the

[ENTER/

YES]

button.

If below 20, press the 

[MENU/NO]

 button and repeat the ad-

justment from step 2.

13. Press the

§ (MD) button and take out the test disc.

The relation between the C1 error and focus bias is as
shown in the following figure. Find points a and b in the fol-
lowing figure using the above adjustment. The focal point posi-
tion c is automatically calculated from points a and b.

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

C1 error

220

b

c

a

Focus bias value
(F. BIAS)

A

B

VC

Specification A = B

A

B

VC

Specification A = B

A

B

VC

Specification A = B

– 38 –

Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Turn the

≠

↔

± dial to display “CPLAY MODE” (C30).

3. Press the

[ENTER/YES]

button to display “CPLAY MID”.

4. The display changes to “C = 

 AD = 

”.

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

  [MENU/NO] 

button to stop playback and press

the

§ (MD) button and take out the test disc.

Checking Procedure :
1. Load a test disc (MDW-74/AU-1).
2. Turn the

≠

↔

± dial to display “CPLAY MODE” (C30).

3. Press the

[ENTER/YES]

button to display “CPLAY MID”.

4. The display changes to “C1 = 

 AD = 

”.

5. If the C1 error rate is below 50, check that ADER is below 2.
6. Press the

[MENU/NO]

 button to stop playback and press

the

§ (MD) button and take out the test disc.

Change the focus bias and check the focus tolerance amount.

Checking Procedure :
1. Load a test disc (MDW-74/AU-1).
2. Turn the

≠

↔

± dial to display “CPLAY MODE” (C30).

3. Press the

[ENTER/YES]

button to display “CPLAY MID”.

4. Press the 

[MENU/NO]

 button when “C = 

 AD = 

” is

displayed.

5. Turn the

≠

↔

± dial to display “FBIAS CHECK” (C05).

6. Press the

[ENTER/YES]

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 50 and ADER is below 2.

7. Press the

[ENTER/YES]

button to display “

/

 b = 

”.

Check that the C1 error is below 220 and ADER is below 2.

8. Press the

[ENTER/YES]

button to display “

/

 a = 

”.

Check that the C1 error is below 220 and ADER is below 2

9. Press the 

[MENU/NO]

 button, next press the

§ (MD) button

and take out the continuously recorded 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 pickup is replaced.
If the adjustment results becomes “Adjust NG!”, the pickup may
be faulty or the servo system circuits may be abnormal.

Adjusting Procedure :
1. Load a check disc (MD) TDYS-1.
2. Turn the

≠

↔

± dial to display “AG Set (CD)” (C26).

3. When the

[ENTER/YES]

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)”.

4. Press the

§ (MD) button and take out the disc.

Adjusting Procedure :
1. Load a test disc (MDW-74/AU-1) for recording.
2. Turn the

≠

↔

± dial to display “AG Set (MO)” (C25).

3. When the

[ENTER/YES]

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)”.

4. Press the

§ (MD) button and take out the disc.

– 39 –

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 10 M

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. Use the following extension cables and relay connector.

• Extension cable (19P) (Part No. J-2501-011-B)

Relay connector (Part No. J-2501-167-A)
(BD (CD) board CN101 to MICROCOMPUTER board CN300)

• Extension cable (17P) (with connector) (Part No. J-2501-167-A)

(CONNECTOR board CN701 to MICROCOMPUTER board CN301)

• Extension cable (4P) (with connector) (Part No. J-2501-165-A)

(LOAD MOTOR board CN713 to MICROCOMPUTER board

CN302)

Procedure:
1. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEO) and TP (VC) by lead wire.
3. Connect between TP (AGCCON) and GND by lead wire.
4. Turn the power ON.
5. Load a disc (YEDS-18) and turn the power ON. again and

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

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

between A and B.  And confirm peak to peak level within
2.4±0.7 Vp-p.

S-curve waveform

7. After check, remove the lead wire connected in step 2.

• 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.

Procedure:
1. Connect oscilloscope to TP (RF).
2. Turn the power ON.
3. Load a disc (YEDS-18) and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-

nal level is correct or not.

Clear RF signal waveform means that the shape “≈” can be clearly
distinguished at the center of the waveform.

RF signal waveform

Procedure:
1. Connect lead wire to TP308 (ADJ) on the MICROCOMPUTER

board.

2. Connect oscilloscope to TP (TEO) on the BD (CD) board.
3. Turn the set ON.
4. Connect lead wire in step1. to GND.
5. Load a disc (YEDS-18) and playback.
6. Press the

[DISPLAY]

button to the tracking servo and the

sleding servo is turned OFF.

7. Check the level B of the oscilloscope’s waveform and the A

(DC voltage) of the center of the Traverse waveform.
Confirm the following:

Traverse waveform

8. Press the

[DISPLAY]

button to the tracking servo and the

sleding servo is turned ON.
Confirm the C (DC voltage) is almost equal to the A (DC volt-
age) in step 7.

Traverse waveform

A

B

symmetry

within 2.4 

±

 0.7 Vp-p

+
–

BD board

TP (RF)
TP (VC)

oscilloscope

VOLT/DIV: 200 mV
TIME/DIV: 500 ns

level:
1.2 

±

 0.2 Vp-p

+
–

BD board

TP (FEO)
TP (VC)

oscilloscope

+
–

BD board

TP (TEO)
TP (VC)

oscilloscope

A (DC 

voltage)

B

0 V

level: 1.3 

±

 0.6 Vp-p

Center of the waveform

C (DC 

voltage)

0 V

Tracking servo ON
Sleding servo ON

Tracking servo OFF
Sleding servo OFF

A

×

 100 = less than ±22 (%)

B

– 40 –

CN101

D101

 

(Side A)

TP170
(I+3V)

TP169
(IOP)

TP233
(TEO)

TP167
(VC)

IC101

IC124

 

(Side B)

 

(Side B)

IC102

TP

(VC)

TP

(RF)

TP

(FEO)

IC101

TP (FEI)

TP (VC)

TP

(TEO)

TP

(AGCCON)

IC103

TP308 (ADJ)

IC300

 

(Side B)