DOWNLOAD Sony MDS-JE780 Service Manual ↓ Size: 2.96 MB | Pages: 68 in PDF or view online for FREE

26

5. Press the  MENU/NO  button and display “LDPWR CHECK”

and stop the laser emission.
(The  MENU/NO  button is effective at all times to stop the laser
emission.)

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

display will be switched between “L 0.73 mW $ 

”,

“L 6.40 mW $ 

”, and “L Wp               $ 

”. Nothing

needs to be performed here.

* This disc is used in focus bias adjustment and error rate check.

The following describes how to create a continuous recording
disc.

1. Insert a disc (blank disc) commercially available.
2. Rotate the  l AMS L  knob and display “CREC1 MODE”

(C35).

3. Press the  YES  button again to display “CREC1 MID”.
4. Press the  LEVEL/DISPLAY/CHAR  button.

Display “CREC (0300)” and start to recording.

5. Complete recording within 5 minutes.
6. Press the  MENU/NO  button and stop recording .
7. Press the  AEJECT  button and remove the disc.

The above has been how to create a continuous recorded data for
the focus bias adjustment and error rate check.
Note :
• Be careful not to apply vibration during continuous recording.

KMS

260B

20101
H0576

Iop = 57.6 mA in this case
Iop (mA) = Digital voltmeter reading (mV)/1 (

Ω

)

Checking 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 CN105 pin 1 (I+3V) and
CN105 pin 2 (Iop).

2. Then, rotate the  l AMS L  knob and display “LDPWR

CHECK”.

3. Press the  YES  button once and display “L 0.93 mW $ 

”.

Check that the reading of the laser power meter become the
specified value.

4. Press the  YES  button once more and display “ L 7.25 mW $

”. Check that the reading the laser power meter and digital

volt meter satisfy the specified value.

Laser power meter reading : L 0.93mW: 0.85-0.91mW (260B)

0.90-0.96mW (260E)

  L 7.25mW: 6.80-7.20mW (260B)

7.00-7.50mW (260E)

Digital voltmeter reading : Optical pick-up displayed value ± 10%

(Optical pick-up label)

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

R

The current Iop value at laser power 7 mw output and reference Iop
value (set at shipment) written in the nonvolatile memory are
compared, and the rate of increase/decrease will be displayed in
percentage.

Note: Perform this function with the optical pick-up set at room

temperature.

Procedure
1. Rotate the  l AMS L  knob to display “Iop Compare”.
2. Press the  YES  button and start measurements.
3. When measurements complete, the display changes to

Iop [STOP]           Iop [7.0mW]           “±xx%yy”.
xx is the percentage of increase/decrease, and OK or NG is
displayed at yy to indicate whether the percentage of increase/
decrease is within the allowable range.

4. Press the  MENU/NO  button to end.

These checks are performed before replacing parts according to
“approximate specifications” to determine the faulty locations. For
details, refer to “Checks Prior to Parts Replacement and Adjust-
ments” (See page 8).

When performing adjustments, set the internal temperature and room
temperature to 22 to 28ºC.
Checks cannot be performed properly if performed after some time
from power ON due to the rise in the temperature of the IC and
diode, etc. So, perform the checks again after waiting some time.

Checking Procedure:
1. Rotate the  l AMS L  knob to display “TEMP CHECK”.

(C12)

2. Press the  YES  button.
3. “T=@@(##) [OK” should be displayed. If “T=@@ (##) [NG”

is displayed, it means that the results are bad.
(@@ indicates the current value set, and ## indicates the value
written in the non-volatile memory.)

Before checking, check the Iop value of the optical pick-up.
(Refer to 5-8. Recording and Displaying Iop Information.)

Digital volt meter

BD board

CN105 pin 

1

 (I+3V)

CN105 pin 

2

 (Iop)

27

7. Press the  YES  button and display “EFB = 

 MO-W”.

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

specified value is satisfied. Do not rotate the  l AMS L
knob.
(Write power traverse checking)

(Traverse Waveform)

11. Press the  YES  button display “EF MO CHECK” (C14).

The disc stops rotating automatically.

12. Press the  A EJECT  button and remove the disc.
13. Load the check disc (MD) TDYS-1.
14. Rotate the  l AMS L  knob and display “EF CD CHECK”

(C15).

15. Press the  YES  button and display “EFB = 

 CD”. Servo is

imposed automatically.

9. Press the  YES  button display “EFB = 

 MO-P”.

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

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

specified value is satisfied. Do not rotate the  l AMS L
knob.

(Traverse Waveform)

Checking Procedure:
1. Connect an oscilloscope to CN105 pin 4 (TE) and CN105 pin

6

 (VC) of the BD board.

2. Load a test disc (MDW-74/GA1). (Refer to Note 1 (see page

28.)

3. Press the  M  button and move the optical pick-up outside the

pit.

4. Rotate the  l AMS L  knob and display “EF MO CHECK”

(C14).

5. Press the  YES  button and display “EFB = 

 MO-R”.

(Laser power READ power/Focus servo ON/tracking servo OFF/
spindle (S) servo ON)

4

6

IA – BI

IA – BI

This test mode performs CREC and CPLAY automatically for
mainly checking the characteristics of the optical pick-up. To
perform this test mode, the laser power must first be checked.
Perform Auto Check after the laser power check and Iop compare.

Procedure
1. Press the  YES  button. If “LDPWR

 ” is displayed, it

means that the laser power check has not been performed. In
this case, perform the laser power check and Iop compare, and
then repeat from step 1.

2. If a disc is in the mechanical deck, it will be ejected forcibly.

“DISC IN” will be displayed in this case. Load a test disc (MDW-
74/GA1) which can be recorded.

3. If a disk is loaded at step 2, the check will start automatically.
4. When “XX CHECK” is displayed, the item corresponding to

XX will be performed.
When “06 CHECK” completes, the disc loaded at step 2 will be
ejected. “DISC IN” will be displayed. Load the check disc (MD)
TDYS-1.

5. When the disc is loaded, the check will automatically be resumed

from “07 CHECK”.

6. After completing to test item 12, check OK or NG will be

displayed. If all items are OK, “CHECK ALL OK” will be
displayed. If any item is NG, it will be displayed as “NG:xxxx”.

When “CHECK ALL OK” is displayed, it means that the optical
pick-up is normal. Check the operations of the other spindle motor,
thread motor, etc.
When displayed as “NG:xxxx”, it means that the optical pick-up is
faulty. In this case, replace the optical pick-up.

All the following checks are performed by the Auto Check mode.
They therefore need not be performed in normal operation.

1. Load a continuously recorded test disc (MDW-74/GA1).

(Refer to “5-5. Using the Continuously Recorded Disc”.)

IA – BI

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

specified value is satisfied. Do not rotate the  AMS  knob.
(Read power traverse checking)

(Traverse Waveform)

28

Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Rotate the  l AMS L  knob and display “CPLAY1 MODE”

(C34).

3. Press the  YES  button twice and display “CPLAY1 MID”.
4. The display changes to “C = 

 AD = 

”.

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

button, 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 test disc (MDW-74/GA1) into the unit.
2. Rotate the  l AMS L  knob to display “CREC 1MODE”

(C35).

3. Press the  YES  button to display the “CREC1 MID”.
4. When recording starts, “  

  ” is displayed, this becomes

“CREC 1 (@@@@)” (@@@@ is the address), and recording
starts.

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

continuous recording.

6. Rotate the  l AMS L  knob to display “CPLAY1MODE”

(C34).

7. Press the  YES  button to display “C PLAY 1MID”.
8. “C = 

 AD = 

” will be displayed.

9. Check that the C error becomes below 50 and the AD error

below 2.

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

EJECT  button and remove the disc.

Note:
Mode which sets the adjustment results recorded in the non-vola-
tile 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 ex-
cluding the temperature compensation offset adjustment.
For details of the initial setting, refer to “5-4. Precautions on Ad-
justments” and execute the initial setting before the adjustment as
required.

Setting Procedure :
1. Rotate the  l AMS L  knob to display “ADJ CLEAR”

(C28).

2. Press the  YES  button. “Complete!” will be displayed momen-

tarily and initial setting will be executed, after which “ADJ
CLEAR” (C28) will be displayed.

Change the focus bias and check the focus tolerance amount.
Checking Procedure :
1. Load a continuously recorded test disc (MDW-74/GA1).

(Refer to “5-5. Using the Continuously Recorded Disc”.)

2. Rotate the  l AMS L  knob and display “CPLAY1

MODE”(C34).

3. Press the  YES  button and display “CPLAY1 MID”.
4. The  display change to “C = 

 AD = 

”.

5. Press the  MENU/NO  button.
6. Rotate the  l AMS L  knob and display “FBIAS CHECK”

(C16).

7. Press the  YES  button and display “ 

/

 c = 

”.

The first four digits indicate the C error rate, the two digits after
[/] indicate ADER, and the 2 digits after [c =] indicate the focus
bias value.
Check that the C error is below 50 and ADER is below 2.

8. Press the  YES  button and display “ 

/

 b = 

”.

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

9. Press the  YES  button and display “ 

/

 a = 

”.

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

10.Press the  MENU/NO  button, next press the  A EJECT  button,

and remove the test disc.

Checking Procedure :
1. Load a continuously recorded test disc (MDW-74/GA1).

(Refer to “5-5. Using the Continuously Recorded Disc”.)

2. Rotate the  l AMS L  knob and display “CPLAY1 MODE”

(C34).

3. Press the  YES  button and display “CPLAY1 MID”.
4. The display changes to “C = 

 AD = 

”.

5. If the C error rate is below 50, check that ADER is 00.
6. Press the  MENU/NO  button, stop playback, press the  A EJECT

button, and test disc.

Ω

4

6

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

specified value is satisfied. Do not rotate the  l AMS L
knob.

(Traverse Waveform)

17. Press the  YES  button and display “EF CD CHECK” (C15).
18. Press the  A EJECT  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

29

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. While pressing the  l AMS L  knob and  x  button, con-

nect the power plug to the outlet, and release the  l AMS
L  knob and  x  button.

2. Rotate the  l AMS L  knob to display “[Service]”, and

press the  YES  button.

3. Rotate the  l AMS L  knob to display “Iop Write” (C05),

and press the  YES  button.

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

and the numbers which can be changed will blink.

5. Input the Iop value written on the optical pick-up.

To select the number : Rotate the  l AMS L  knob.
To select the digit : Press the  l AMS L  knob

6. When the  YES  button is pressed, the display becomes

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

7. As the adjustment results are recorded for the 6 value. Leave it

as it is and press the  YES  button.

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

recorded in the non-volatile memory and the display will be-
come “Iop Write” (C05).

Display Procedure :
1. Rotate the  l AMS L  knob to display “Iop Read” (C26).
2. “@@.@/##.#” 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 AMS L  button or  MENU/NO

button to display “Iop Read” (C26).

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 AMS L  knob and display “TEMP ADJUS”

(C03).

2. Press the  YES  button.
3. “TEMP = 

[OK]” and the current temperature data will be

displayed.

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

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

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

 SAVE” will be

displayed and turned back to “TEMP ADJUS” (C03) display
then. When the  MENU/NO  button is pressed, “TEMP ADJUS”
(C03) will be displayed immediatelly.

The “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 Iop Information.)
Connection :

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 CN105 pin 1 (I+3V) and
CN105 pin 2 (Iop).

2. Rotate the  l AMS L  knob and display “LDPWR

ADJUS” (C04).
(Laser power : For adjustment)

3. Press the  YES  button once and display “L 0.93 mW $ 

”.

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

power meter becomes the specified value. Press the  YES
button after setting the range knob of the laser power meter, and
save the adjustment results. (“L SAVE $ 

” will be displayed

for a moment.)

5. Then “L 7.25 mW $ 

” will be displayed.

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

laser power meter becomes the specified value, press the
YES   button and save it.

Note : Do not perform the emission with 7.25 mW more than 15

seconds continuously.

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

CHECK” (C13).

8. Press the  YES  button once and display “L 0.93 mW $ 

”.

Check that the reading of the laser power meter become the speci-
fied value.

9. Press the  YES  button once more and display “L 7.25 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 : L 0.93mW : 0.85-0.91mW (260B)

0.90-0.96mW (260E)

  L 7.25mW : 6.90-7.10mW (260B)

7.20-7.30mW (260E)

Digital voltmeter reading : Optical pick-up displayed value ± 10%

(Optical pick-up label)

Digital volt meter

BD board

CN105 pin 

1

 (I+3V)

CN105 pin 

2

 (Iop)

KMS

260B

20101
H0576

Iop = 57.6 mA in this case
Iop (mA) = Digital voltmeter reading (mV)/1 (

Ω

)

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

R