42
9. Press the
ENTER/YES “R”
button to 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 press the
. m
“R”
or
M >
“R”
button.
Traverse Waveform
11. Press the
ENTER/YES “R”
button to display “EF MO CHECK”
(C14).
The disc stops rotating automatically.
12. Press the
[MD ]
button and take out the disc.
13. Load the check disc (TDYS-1).
14. Press the
. m
“R”
or
M >
“R”
button and display
“EF CD CHECK” (C15).
15. Press the
ENTER/YES “R”
button to display “EFB =
CD”.
Servo is imposed automatically.
16. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not press the
. m
“R”
or
M >
“R”
button.
Traverse Waveform
17. Press the
ENTER/YES “R”
button to display “EF CD CHECK”
(C15).
18. Press the
[MD ]
button and take out the check disc (TDYS-
1).
Checking Location: BD (MD) board (see page 47)
6-7. Focus Bias Check
Change the focus bias and check the focus tolerance amount.
Procedure:
1. Load the test disc (MDW-74/GA-1).
2. Press the
. m
“R”
or
M >
“R”
button to display
“CPLAY2MODE” (C36).
3. Press the
ENTER/YES “R”
button to display “CPLAY2MID”.
4. Press the
MENU/NO “R”
button when “C =
AD =
)” is
displayed.
5. Press the
. m
“R”
or
M >
“R”
button to display
“FBIAS CHECK” (C16).
6. Press the
ENTER/YES “R”
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 20 and ADER is below 2.
7. Press the
ENTER/YES “R”
button to display “
/
b =
”.
Check that the C1 error is about 200 and ADER is below 2.
8. Press the
ENTER/YES “R”
button to display “
/
a =
”.
Check that the C1 error is about 200 and ADER is below 2.
9. Press the
MENU/NO “R”
button, then press the
[MD ]
button
and take out the test disc.
6-8. C PLAY Check
MO Error Rate Check
Procedure:
1. Load the test disc (MDW-74/GA-1).
2. Press the
. m
“R”
or
M >
“R”
button to display
“CPLAY2MODE” (C36).
3. Press the
ENTER/YES “R”
button to display “CPLAY2MID”.
4. The display changes to “C =
AD =
)”.
5. If the C1 error rate is below 20, check that ADER is 00.
6. Press the
MENU/NO “R”
button to stop playback, then press
the
[MD ]
button and take out the test disc.
CD Error Rate Check
Procedure:
1. Load the check disc (TDYS-1).
2. Press the
. m
“R”
or
M >
“R”
button to display
“CPLAY2MODE” (C36).
3. Press the
ENTER/YES “R”
button to display “CPLAY2MID”.
4. The display changes to “C =
AD =
)”.
5. Check that the C1 error rate is below 20.
6. Press the
MENU/NO “R”
button to stop playback, then press
the
[MD ]
button and take out the check disc.
6-9. Self-Recording/playback Check
Prepare a continuous recording disc using the unit to be repaired
and check the error rate.
Procedure:
1. Load a recordable disc (blank disc).
2. Press the
. m
“R”
or
M >
“R”
button to display
“CREC 2MODE” (C37).
3. Press the
ENTER/YES “R”
button to display “CREC 2MID”.
4. When recording starts, lights up “
REC
” and display “CREC
2 @@@@” (@@@@ is the address).
5. About 1 minute later, press the
MENU/NO “R”
button to stop
continuous recording.
6. Press the
. m
“R”
or
M >
“R”
button to display
“CPLAY2MODE” (C36).
7. Press the
ENTER/YES “R”
button to display “CPLAY2 MID”.
8. “C =
AD =
)” will be displayed.
9. Check that the C1 error becomes below 20 and the AD error
below 2.
10. Press the
MENU/NO “R”
button to stop playback, then press
the
[MD ]
button and take out the disc.
A
B
VC
Specified value : Below 10% offset value
Offset value (%) = X 100
I
A – B
I
2 (A + B)
A
B
VC
Specified value : Below 10% offset value
Offset value (%) = X 100
I
A – B
I
2 (A + B)
Z
Z
Z
Z
Z
Z
