DOWNLOAD Sony MDS-SP55 Service Manual ↓ Size: 3.87 MB | Pages: 57 in PDF or view online for FREE

25

Change the focus bias and check the focus tolerance amount.
Checking Procedure :
1. Load a test disk (MDW-74/GA-1).
2. Rotate the  l L  knob and display “MD CPLAY MODE”.
3. Press the  ENTER/YES  button twice and display “MD CPLAY

MID”.

4. Press the  MENU/NO  button when “MD C = 

 AD = 

” is

displayed.

5. Rotate the  l L  knob and display “FBIAS CHECK”.
6. Press the  ENTER/YES  button and display “MD 

/

 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 220 and ADER is below 2.

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

/

 b =

”.

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

8. Press the  ENTER/YES  button and display “MD 

/

 a =

”.

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

9. Press the  MENU/NO  button, next press the  A  button, and

remove the test disc.

Checking Procedure :
1. Load a test disk (MDW-74/GA-1).
2. Rotate the  l L  knob and display “MD CPLAY MODE”.
3. Press the  ENTER/YES  button and display “MD CPLAY MID”.
4. The display changes to “MD C1 = 

 AD = 

”.

5. If the C1 error rate is below 80, check that ADER is below 2.
6. Press the  MENU/NO  button, stop playback, press the  A  but-

ton, and test disc.

Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Rotate the  l L  knob and display “MD CPLAY MODE”.
3. Press the  ENTER/YES  button twice and display “MD CPLAY

MID”.

4. The display changes to “MD C1 = 

 AD = 

”.

5. Check that the C1 error rate is below 50.
6. Press the  MENU/NO  button, stop playback, press the  A  but-

ton, and the test disc.

Prepare a continuous recording disc using the unit to be repaired
and check the error rate.

Checking Procedure :
1. Insert a recordable disc (blank disc) into the unit.
2. Rotate the  l L  knob to display “MD CREC MODE”.
3. Press the  ENTER/YES  button to display the “MD CREC MID”.
4. When recording starts, this becomes “MD CREC (@@@@)”

(@@@@ is the address), and recording starts.

5. About 1 minute later, press the  MENU/NO  button to stop con-

tinuous recording.

6. Rotate the  l L  knob to display “MD CPLAY MODE”.
7. Press the  ENTER/YES  button to display “MD CPLAY MID”.
8. “MD C1 = 

 AD = 

” will be displayed.

9. Check that the C1 error becomes below 80 and the AD error

below 2.

10. Press the  MENU/NO  button to stop playback, and press the

A  button and remove the disc.

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

specified value is satisfied. Do not rotate the  m  button or
M  button.

(Traverse Waveform)

11. Press the  ENTER/YES  button display “MD EF MO CHECK”

The disc stops rotating automatically.

12. Press the  A  button and remove the disc.
13. Load the check disc (MD) TDYS-1.
14. Roteto the  l L  knob and display “MD EF CD CHECK”.
15. Press the  ENTER/YES  button and display “MD EFB = 

CD”. Servo is imposed automatically.

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

specified value is satisfied. Do not rotate the  m  button or
M  button.

(Traverse Waveform)

17. Press the  ENTER/YES  button and display “MD EF CD

CHECK”.

18. Press the  A  button and remove the check disc (MD) TDYS-1.

Note 1 : MO reading data will be erased during if a recorded disc is

used in this adjustment.

Note 2 : If the traverse waveform is not clear, connect the oscillo-

scope as shown in the following figure so that it can be
seen more clearly.

IA – BI

IA – BI

Ω

3

1

26

Note:
Mode which sets the adjustment results recorded in the non-volatile
memory to the initial setting value. However the results of the
temperature compensation offset adjustment will not change to the
initial setting value.
If initial setting is performed, perform all adjustments again
excluding the temperature compensation offset adjustment.
For details of the initial setting, refer to “5-4. Precautions for Ad-
justments” and execute the initial setting before the adjustment as
required.

Setting Procedure :
1. Rotate the  l L  knob to display “MD ADJ CLEAR”.
2. Press the  ENTER/YES  button. “Complete!!” will be displayed

momentarily and initial setting will be executed, after which “MD
ADJ CLEAR” will be displayed.

The IOP data can be recorded in the non-volatile memory. The IOP
value on the label of the optical pick-up and the IOP value after the
adjustment will be recorded. Recording these data eliminates the
need to read the label on the optical pick-up.

Recording Procedure :
1. When the power OFF (STANDBY), press the  ?/1  button (TA)

while pressing the  s  button and  ENTER/YES  button to-
gether.

2. Press the  MENU/NO  button, and when “Check” is displayed.
3. Rotate the  l  L  knob to display “MD [Service]”, and

press the  ENTER/YES  button.

4. Rotate the  l L  knob to display “MD Iop Write”, and

press the  ENTER/YES  button.

5. The display becomes Ref=@@@.@ (@ is an arbitrary number)

and the numbers which can be changed will blink.

6. Input the IOP value written on the optical pick-up.

To select the number : Rotate the  l L  knob.
To select the digit : Press the  SYNCHRO REC  button.

7. When the  ENTER/YES  button is pressed, the display becomes

“MD Measu=@@@.@” (@ is an arbitrary number).

8. As the adjustment results are recorded for the 7 value. Leave it

as it is and press the  ENTER/YES  button.

9. “Complete!!” will be displayed momentarily. The value will be

recorded in the non-volatile memory and the display will be-
come “MD Iop Write”.

Display Procedure :
1. Rotate the  l L  knob to display “MD Iop Read”.
2. “MD @@.@/##.#” is displayed and the recorded contents are

displayed.
@@.@ indicates the IOP value labeled on the pick-up.
##.# indicates the IOP value after adjustment

3. To end, press the  l L  button or  MENU/NO  button to

display “MD Iop Read”.

Save the temperature data at that time in the non-volatile memory
as 25 ˚C reference data.
Note :
1. Usually, do not perform this adjustment.
2. Perform this adjustment in an ambient temperature of 22 ˚C to

28 ˚C. Perform it immediately after the power is turned on when
the internal temperature of the unit is the same as the ambient
temperature of 22 ˚C to 28 ˚C.

3. When D101 has been replaced, perform this adjustment after

the temperature of this part has become the ambient tempera-
ture.

Adjusting Procedure :
1. Rotate the  l L  knob and display “MD TEMP ADJUST”.
2. Press the  ENTER/YES  button and select the “MD TEMP

ADJUST” mode.

3. “MD TEMP = 

[OK]” and the current temperature data will

be displayed.

4. To save the data, press the  ENTER/YES  button.

When not saving the data, press the  MENU/NO  button.

5. When the  ENTER/YES  button is pressed, “MD TEMP = 

SAVE” will be displayed and turned back to “MD TEMP
ADJUST” display then. When the  MENU/NO  button is pressed,
“MD TEMP ADJUST” will be displayed immediatelly.

The “MD TEMP =  

” should be within “E0 - EF”, “F0 - FF”, “00

- 0F”,  “10 - 1F” and “20 - 2F”.

Check the IOP value of the optical pick-up before adjustments.
(Refer to 5-8. Recording and Displaying the IOP Information.)

Adjusting 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. Rotate the  l  L  knob and display “MD LDPWR AD-

JUST”.
(Laser power : For adjustment)

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

mW $ 

”.

4. Rotate the  l  L  knob so that the reading of the laser

power meter becomes 0.85 to 0.91 mW. Press the  ENTER/YES
button after setting the range knob of the laser power meter, and
save the adjustment results. (“MD LD SAVE $ 

” will be dis-

played for a moment.)

5

4

27

KMS

260A

27X40
B0825

T

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

Ω

)

5. Then “MD LD 7.0 mW $ 

” will be displayed.

6. Rotate the  l  L  knob so that the reading of the laser

power meter becomes 6.9 to 7.1 mW, press the   ENTER/YES
button and save it.

Note : Do not perform the emission with 7.0 mW more than 15

seconds continuously.

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

CHECK”.

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

*** $  ”. Check that the reading of the laser power meter be-
come 0.85 to 0.91 mW. (

*** means the IOP value)

9. 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.
Note down the digital voltmeter reading value.

Laser power meter reading : 7.0 ± 0.1 mW
Digital voltmeter reading : Optical pick-up displayed value ± 10%

(Optical pick-up label)

10. 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.)

11. Rotate the  l L  knob to display “MD Iop Write”.
12. Press the  ENTER/YES  button. When the display becomes

Ref=@@@.@ (@ is an arbitrary number), press the  ENTER/
YES  button to display “MD Measu=@@@.@” (@ is an arbi-
trary number).

13. The numbers which can be changed will blink. Input the IOP

value noted down at step 9.
To select the number : Rotate the  l L  knob.
To select the digit : Press the  SYNCHRO REC  button.
Selection of digit : Press the  SYNCHRO REC  button.

14. When the  ENTER/YES  button is pressed, “Complete!” will

be displayed momentarily. The value will be recorded in the
non-volatile memory and the display will become “MD Iop
Write”.

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

the display will be switched between “MD 0.7 mW 

*** $

”, “MD 6.2 mW 

*** $  ”, and “MD Wp               ***

$ 

”. Nothing needs to be performed here.

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

Adjusting 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

ADJUST”.

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. Rotate the  l L  knob so that the waveform of the oscillo-

scope becomes the specified value.
(When the  l L  knob is rotated, the 

 of “MD EFB=

” changes and the waveform changes.) In this adjustment,

waveform varies at intervals of approx. 2%. Adjust the wave-
form so that the specified value is satisfied as much as possible.
(Read power traverse adjustment)

(Traverse Waveform)

7. Press the  ENTER/YES  button and save the result of adjustment

to the non-volatile memory (“MD EFB = 

 SAVE” will be dis-

played for a moment. Then “MD EFB = 

 MO-W” will be

displayed).

8. Rotate the  l L  knob so that the waveform of the oscillo-

scope becomes the specified value.
(When the  l L  knob is rotated, the 

 of “MD EFB- 

”

changes and the waveform changes.) In this adjustment, wave-
form 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)

3

1

28

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

 SAVE”

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

19. Press the  A  button and remove the check disc (MD) TDYS-1.

Note 1 : MO reading data will be erased during if a recorded disc is

used in this adjustment.

Note 2 : If the traverse waveform is not clear, connect the oscillo-

scope as shown in the following figure so that it can be
seen more clearly.

9. Press the  ENTER/YES  button, and save the adjustment results

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

 SAVE” will be

displayed for a moment.)

10. “MD EFB = 

 MO-P”. will be displayed.

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

11. Rotate the  l L  knob until the waveform of the oscillo-

scope 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  button, and save the adjustment results

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

 SAVE” will be

displayed for a moment.)
Next “MD EF MO ADJUST” is displayed. The disc stops rotat-
ing automatically.

13. Press the  A  button and remove the disc.
14. Load the check disc (MD) TDYS-1.
15. Roteto  l L  knob and display “MD EF CD ADJUST”.
16. Press the  ENTER/YES  button and display “MD EFB = 

CD”. Servo is imposed automatically.

17. Rotate the  l L  knob so that the waveform of the oscil-

loscope 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)

Adjusting Procedure :
1. Load a test disk (MDW-74/GA-1).
2. Rotate the  l L  knob and display “MD CPLAY MODE”.
3. Press the  ENTER/YES  button and display “MD CPLAY MID”.
4. Press the  MENU/NO  button when “MD C1 = 

 AD = 

”

is displayed.

5. Rotate the  l L  knob and display “MD FBIAS ADJUST”.
6. Press the  ENTER/YES  button and display “MD 

/

 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. Rotate the  l L  knob in the clockwise direction and find

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

8. Press the  ENTER/YES  button and display “MD 

/

 b =

”.

9. Rotate the  l L  knob in the counterclockwise direction

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

10. Press the  ENTER/YES  button and display “MD 

/

 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
adjustment from step 2.

13. Press the  A   button to remove the test disc.
Note 1 : 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 automatically calculated from points a
and b.

Note 2 : As the C1 error rate changes, perform the adjustment us-

ing the average vale.

Ω

3

1