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5-6.
CHECK PRIOR TO REPAIRS
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 11).
5-6-1. Temperature Compensation Offset Check
When performing adjustments, set the internal temperature and
room temperature of 22 °C to 28 °C.
Checking Procedure:
1. Press the
l m
or
M L
CHECK".
2. Press the
ENTER/YES "R"
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)
5-6-2. Laser Power Check
Before checking, check the IOP value of the optical pick-up.
(Refer to 8. Recording and Displaying IOP Information)
Connection :
Optical pick-up
objective lens
BD (MD) board
CN110 pin 5 (I+3V)
CN110 pin 4 (IOP)
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
button or
button to move the optical pick-up)
M L
Connect the digital voltmeter to CN110 pin 5 (I+3V) and
CN110 pin 4 (IOP) on the BD (MD) board.
2. Then, press the
l m
"LDPWR CHECK".
3. Press the
ENTER/YES "R"
$
". Check that the reading of the laser power meter become
0.84 to 0.92 mW.
4. Press the
ENTER/YES "R"
7.0 mW $
". Check that the reading the laser power meter
and digital voltmeter satisfy the specified value.
Specified Value:
Laser power meter reading : 7.0 ± 0.2 mW
Digital voltmeter reading : Value on the optical pick-up label
±10%
(Optical pick-up label)
KMS260A
27X40
B0825
lOP=82.5 mA in this case
lOP (mA) = Digital voltmeter reading (mV)/1 (Ω)
5. Press the
button to display "LDPWR CHECK"
MENU/NO "R"
and stop the laser emission.
(The
button is effective at all times to stop the
MENU/NO "R"
laser emission)
32
button to display "TEMP
button.
laser
power meter
digital voltmeter
+
–
l m
or
button to display
M L
button once to display "LD 0.9 mW
button once more to display "LD
Note 1: After step 4, each time the
the display will be switched "LD 0.7 mW $
", and "LD Wp
here.
5-6-3. Traverse Check
Note 1:Data will be erased during MO reading if a recorded disc is
used in this adjustment.
Note 2:If the traverse waveform is not clear, connect the oscilloscope
as shown in the following figure so that it can be seen more
clearly.
BD (MD) board
CN110 pin 3 (TEO)
CN110 pin 1 (VC)
Connection :
BD (MD) board
CN110 pin 3 (TEO)
CN110 pin 1 (VC)
Checking Procedure:
1. Connect an oscilloscope to CN110 pin 3 (TEO) and CN110
pin 1 (VC) on the BD (MD) board.
2. Load a disc (any available on the market). (Refer to Note 1)
3. Press the
button to move the optical pick-up outside
M L
the pit.
4. Press the
or
l m
M L
CHECK".
5. Press the
ENTER/YES "R"
(Laser power READ power/Focus servo ON/tracking servo
OFF/spindle (S) servo ON)
6. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not press the
M L
button.
(Read power traverse checking)
Traverse Waveform
VC
Specified value : Below 10% offset value
Offset value (%) =
7. Press the
ENTER/YES "R"
8. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not press the
button.
M L
(Write power traverse checking)
Traverse Waveform
VC
Specified value : Below 10% offset value
Offset value (%) =
button is pressed,
ENTER/YES "R"
", "LD 6.2 mW $
$
". Nothing needs to be performed
oscilloscope
(DC range)
330 k Ω
+
–
10 pF
oscilloscope
(DC range)
+
V: 0.1 V/div
–
H: 10 ms/div
button to display "EF MO
button to display "EFB =
MO-R".
l m
A
B
IA – BI
X 100
2 (A + B)
button to display "EFB =
MO-W".
l m
A
B
IA – BI
X 100
2 (A + B)
or
or
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