Sony MDS-SD1 Service Manual page 26

10. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not rotate the – ˜ + knob.
(Traverse Waveform)
VC
Specified value : Below 10% offset value
I A – B I
Offset value (%) =
2 (A + B)
11. Press the ENTER/YES button display "EF MO CHECK"
The disc stops rotating automatically.
12. Press the § button and remove the disc.
13. Load the check disc (MD) TDYS-1.
14. Roteto the – ˜ + knob and display "EF CD CHECK".
15. Press the ENTER/YES button and display "EFB =
Servo is imposed automatically.
16. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not rotate the – ˜ + knob.
(Traverse Waveform)
VC
Specified value : Below 10% offset value
I A – B I
Offset value (%) =
2 (A + B)
17. Press the ENTER/YES button and display "EF CD CHECK".
18. Press the § 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.
BD board
CN110 pin 3 (TE)
CN110 pin 1 (VC)
X 100
X 100
Oscilloscope
330 k Ω
10pF
5-6-4. Focus Bias Check
Change the focus bias and check the focus tolerance amount.
Checking Procedure :
1. Load a test disk (MDW-74/AU-1).
2. Rotate the – ˜ + knob and display "CPLAY MODE".
3. Press the ENTER/YES button twice and display "CPLAY MID".
A
4. Press the MENU/NO button when "C1 =
displayed.
5. Rotate the – ˜ + knob and display "FBIAS CHECK".
B
6. Press the ENTER/YES button and display "
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 "
Check that the C1 error is below 220 and ADER is below 2.
8. Press the ENTER/YES button and display "
Check that the C1 error is below 220 and ADER is below 2.
9. Press the MENU/NO button, next press the § button, and
remove the test disc.
CD".
5-6-5. C PLAY Checking
MO Error Rate Check
Checking Procedure :
1. Load a test disk (MDW-74/AU-1).
2. Rotate the – ˜ + knob and display "CPLAY MODE".
3. Press the ENTER/YES button and display "CPLAY MID".
4. The display changes to "C1 =
A
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 § but-
ton, and test disc.
B
CD Error Rate Check
Checking Procedure :
1. Load a check disc (MD) TDYS-1.
2. Rotate the – ˜ + knob and display "CPLAY MODE".
3. Press the ENTER/YES button twice and display "CPLAY MID".
4. The display changes to "C1 =
5. Check that the C1 error rate is below 50.
6. Press the MENU/NO button, stop playback, press the § but-
ton, and the test disc.
5-6-6. Self-Recording/playback Check
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 – ˜ + knob to display "CREC MODE".
3. Press the ENTER/YES button to display the "CREC MID".
4. When recording starts, "
"CREC @@@@" (@@@@ is the address), and recording starts.
5. About 1 minute later, press the MENU/NO button to stop
continuous recording.
6. Rotate the – ˜ + knob to display "C PLAY MODE".
7. Press the ENTER/YES button to display "C PLAY MID".
8. "C1 = AD =
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
§ button and remove the disc.
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AD =
AD = ".
AD = ".
REC
" is displayed, this becomes
" will be displayed.
" is
/ c = ".
/ b = ".
/ a = ".