– 23 –
6. CHECK PRIOR TO REPAIRSThese 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).
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. Turn the = AMS +knob to display “TEMP CHECK”
(C01).
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)
6-2. Laser Power Check
Before checking, check the IOP value of the optical pick-up.
(Refer to 5-8. Recording and Displaying IOP Information)
Connection :
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 0 but-
ton or )button to move the optical pick-up)
Connect the digital volt meter to CN110 pin 5 (I+3V) and
CN110 pin 4 (IOP).
2. Then, turn the = AMS +knob and display “LDPWR
CHECK” (C02).
3. Press the [YES] button once and display “LD 0.9 mW $ ”.
Check that the reading of the laser power meter become 0.84
to 0.92 mW.
4. Press the [YES] button once more and display “LD 7.0 mW $
”. Check that the reading the laser power meter and digital
volt meter satisfy the specified value.
Specification:
Laser power meter reading: 7.0 ± 0.2 mW
Digital voltmeter reading : Optical pick-up displayed value
±10%
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)
Optical pick-up
objective lens
laser
power mete
r
+
–
BD board
digital voltmete
r
CN110 pin
5
(I +3V)
CN110 pin
4
(IOP)
[]
[]
KMS260A
27X40
B0825
lOP=82.5 mA in this case
lOP (mA) = Digital voltmeter reading (mV)/1 (
Ω
)
(Optical pick-up label)
Note 1: After step 4, each time the [YES] button is pressed, the display
will be switched between “LD 0.7 mW $ ”, “LD 6.2 mW $
”, and “LD Wp $ ”. Nothing needs to be performed
here.
6-3. Traverse Check
Connection :
Checking Procedure:
1. Connect an oscilloscope to CN110 pin 3 (TEO) and CN110
pin 1 (VC) of the BD board.
2. Load a disc (any available on the market). (Refer to Note 1)
3. Press the )button and move the optical pick-up outside
the pit.
4. Turn the = AMS +knob and display “EF MO
CHECK”(C03).
5. Press the [YES] button and display “EFB = MO-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 turn the = AMS +
knob.
(Read power traverse checking)
(Traverse Wav ef orm)
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 turn the = AMS +
knob.
(Write power traverse checking)
(Traverse Wav ef orm)
+
–
oscilloscope
(DC range)
V: 0.1 V/div
H: 10 ms/div
BD board
CN110 pin
3
(TEO)
CN110 pin
1
(VC)
[]
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)
+
–
oscilloscope
(DC range)
10 pF
330 k
Ω
CN110 pin
3
(TEO)
CN110 pin
1
(VC)
BD board
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.