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CD ELECTRICAL MEASUREMENT
QQ
3 7 63 1515 0
• Perform the measurement after the machine enters the test mode.
• Place the CD mechanism horizontally level.
• Equipment and tools required
Measuring equipment: Oscilloscope (Use the probe of 10:1)
Digital Multimeter (Use it in the DC Volt range.)
Jitter meter (Kikusui 6235 or equivalent)
Test disc:
TCD-782
ATD-001
1. RF Waveform Check
1) Connect an oscilloscope to test point (IC101 4pin, RF), (IC101 11pin, Vref).
2) Play back the 2nd track of the TCD-782.
3) Check to see that the RF waveform has the maximum amplitude
and the center of the wedge waveform has the clear blank.
2. Jitter Check
1) While an oscilloscope is kept connected in the same test point
as in the 2. RF Waveform Check, connect the output terminal
TE
L 13942296513
of an oscilloscope to the input terminal of a jitter meter.
2) Set the VOLT range selector of an oscilloscope to 500 mV
range or lower.
3) Play back the 2nd track of the TCD-782.
4) Check to see that a jitter meter indicates 40.0 ns or less.
3. Tracking Balance Check
1) Connect an oscilloscope to test point (TE), (VREF).
2) Play back the 2nd track of the TCD-782 and press the PAUSE
button.
3) Check to see that the traverse waveform on an oscilloscope is
vertically symmetrical.
4. Play-ability Check
1) Play back the 4th, 9th and 13th track of ATD-001. Check to see
that noise does not occur and sound skipping does not occur.
5. Laser Current Check
*Do not perform this measurement unless the laser is suspected to be
defective.
1) Connect a Digital Multimeter across the resistor R8 (3.3 ohms).
2) Play back the TCD-782 and check the DC voltage value on a Digital
www
Multimeter.
3) Calculate the laser current (Iop) by dividing the DC voltage across
R8 by the resistor value.
Laser current (Iop) = DC voltage across R8 divided by the
.
resistor value (3.3 ohms).
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2 9
8
OSCILLOSCOPE
+
--
RF
VREF
OSCILLOSCOPE
Q Q
3
6 7
1 3
1 5
+
--
RF
VREF
OSCILLOSCOPE
+
--
TE
VREF
R8
R8
co
R EXAMPLE
.
-20-
9 4
2 8
EYE PATTERN
must be CLEAR and MAX.
OUTPUT
VOLT/DIV: 500mV
TIME/DIV: 0.5µS
AC INPUT
JITTER METER
0 5
8
2 9
9 4
2 8
OUTPUT
INPUT
ns
VREF
OUTPUT
A=B
VOLT/DIV: 500mV
TIME/DIV: 1mS
DC INPUT
DIGITAL MULTIMETER
V
+
--
m
J1171ZS
0009372
SPEC VALUE
37.2mA
9 9
1.6 Vp-p
0V
9 9
A
B
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