DOWNLOAD Sony MDS-JE520 Service Manual ↓ Size: 4.89 MB | Pages: 81 in PDF or view online for FREE

Model
MDS-JE520
Pages
81
Size
4.89 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
mds-je520.pdf
Date

Sony MDS-JE520 Service Manual ▷ View online

– 41 –
11. Rotate the  AMS  knob 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  YES  button, and save the adjustment results in the
non-volatile memory. (“EFB = 
 SAV” will be displayed for a
moment.)
Next “EF MO ADJUS” is displayed. The disc stops rotating
automatically.
13. Press the  §EJECT  button and remove the disc.
14. Load the check disc (MD) TDYS-1.
15. Roteto  AMS  knob and display “EF CD ADJUS” (C12).
16. Press the  YES  button and display “EFB = 
 CD”. Servo is
imposed automatically.
17. Rotate the  AMS  knob 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  YES  button, display “EFB = 
 SAV” for a moment
and save the adjustment results in the non-volatile memory.
Next “EF CD ADJUS” will be displayed.
19. Press the  §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.
5-12. FOCUS BIAS ADJUSTMENT
Adjusting Procedure :
1. Load a test disk (MDW-74/AU-1).
2. Rotate the  AMS  knob and display “CPLAY MODE” (C29).
3. Press the  YES  button and display “CPLAY MID”.
4. Press the  MENU/NO  button when “C = 
 AD = 
” is
displayed.
5. Rotate the  AMS  knob and display “FBIAS ADJUST” (C13).
6. Press the  YES  button and 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. Rotate the  AMS  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  YES  button and display “ 
/
 b = 
”.
9. Rotate the  AMS  knob in the counterclockwise direction and
find the focus bias value at which the C1 error rate becomes
220.
10. Press the  YES  button and display “ 
/
 c = 
”.
11. Check that the C1 error rate is below 50 and ADER is 00. Then
press the  YES  button.
12. If the “(
)” in “
 - 
 - 
 (
)” is above 20, press the  YES
button.
If below 20, press the  MENU/NO  button and repeat the
adjustment from step 2.
13. Press the  §EJECT   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.
VC
A
B
Specification A = B
VC
A
B
Specification A = B
330 k
Oscilloscope
10pF
BD board
CN110 pin 
3
 (TE)
CN110 pin 
2
 (VC)
C1 error
220
b
c
a
Focus bias value
(F. BIAS)
– 42 –
5-13. ERROR RATE CHECK
5-13-1. CD Error Rate Check
Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Rotate the  AMS  knob and display “CPLAY MODE” (C29).
3. Press the  YES  button twice and 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, stop playback, press the   §EJECT
button, and remove the test disc.
5-13-2. MO Error Rate Check
Checking Procedure :
1. Load a test disc (MDW-74/AU-1).
2. Rotate the  AMS  knob and display “CPLAY MODE” (C29).
3. Press the  YES  button and display “CPLAY MID”.
4. The display changes to “C1 = 
 AD = 
”.
5. If the C1 error rate is below 50, check that ADER is 00.
6. Press the  MENU/NO  button, stop playback, press the  §EJECT
button, and remove the test disc.
5-14. FOCUS BIAS CHECK
Change the focus bias and check the focus tolerance amount.
Checking Procedure :
1. Load a test disc (MDW-74/AU-1).
2. Rotate the  AMS  knob and display “CPLAY MODE” (C29).
3. Press the  YES  button twice and display “CPLAY MID”.
4. Press the  MENU/NO  button when “C = 
 AD = 
” is
displayed.
5. Rotate the  AMS  knob and display “FBIAS CHECK” (C05).
6. Press the  YES  button and 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  YES  button and display “ 
/
 b = 
”.
Check that the C1 error is below 220 and ADER is below 2.
8. Press the  YES  button and display “ 
/
 a = 
”.
Check that the C1 error is below 220 and ADER is below 2
9. Press the  MENU/NO  button, next press the  §EJECT  button,
and remove the continuously recorded disc.
Note 1 : 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 car-
ried out properly. Adjust perform the beginning again.
5-15. AUTO GAIN CONTROL OUTPUT LEVEL
ADJUSTMENT
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.
5-15-1. CD Auto Gain Control Output Level Adjustment
Adjusting Procedure :
1. Insert the check disc (MD) TDYS-1.
2. Rotate the  AMS  knob to display “AG Set (CD)” (C26).
3. When the  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  §EJECT  button to remove the disc.
5-15-2. MO Auto Gain Control Output Level Adjustment
Adjusting Procedure :
1. Insert the reference disc (MDW-74/AU-1) for recording.
2. Rotate the  AMS  knob to display “AG Set (MO)” (C25).
3. When the  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  §EJECT  button to remove the disc.
– 43 –
NOTE:It is useful to use the jig. for checking the waveform. (Refer
to Servicing Note on page 6.)
5-15. ADJUSTING POINTS AND CONNECTING POINTS
[BD BOARD] (SIDE A)
[BD BOARD] (SIDE B)
CN110
NOTE
D101
I+3V
IOP
TE
VC
RF
GND
IC171
IC121
IC101
IC192
CN101
– 44 –
SECTION  6
DIAGRAMS
6-1. CIRCUIT BOARDS LOCATION
MAIN board
SW board
BD board
POWER SW board
HP board
DISPLAY board
KEY SW board
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