Aiwa CX-LZX7 Service Manual page 45

< CD SECTION >
CD PWB
PATTERN SIDE
R2
Q1
IC1
IC120
CD Adjustment Method
• Perform the adjustments after the machine enters the test mode.
• Place the CD mechanism on level ground.
• Equipment and tools required
Measuring equipment:
Test Disc:
1. Focus Bias Adjustment
1) Connect a digital multimeter to the test point (FE), (VC).
2) Play back the 2nd track of TCD-782.
3) Adjust SFR130 until the digital multimeter indicates 0 ± 10 mV.
2. RF Waveform Check
1) Connect an oscilloscope to test point (RF), (VC).
2) Play back the 2nd track of TCD-782.
3) Check that the RF waveform has the maximum amplitude and
the center of the wedge waveform has the clear blank.
3. Jitter Check
1) While an oscilloscope is kept connected in the same test point as
in step 2. RF Waveform Check, connect the output terminal of an
oscilloscope to the input terminal of the jitter meter.
2) Set the VOLT range selector of an oscilloscope to 500 mV range
or lower.
3) Play back the 2nd track of TCD-782.
4) Check that the jitter meter indicates 28.0 ns or less.
4. Play Ability Check
1) Play back the 3rd, 8th, and 13th track of ATD-001. Check that the
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 R2 (10 Ω).
2) Play back the TCD-782 and check the DC voltage value on the
digital multimeter.
3) Calculate the laser current (Iop) by dividing the DC voltage across
R2 by the resistor value (R2 = 10 Ω). Check that the laser current
(Iop) is 80 mA or less.
IC2
RF
R35
R40
IC501
Oscilloscope (Use the probe of 10:1)
Digital Multimeter (Use it in the DC Volt range)
Jitter meter (Kikusui 6235)
TCD-782
ATD-001
2 3
5
OSCILLOSCOPE
RF
VC
– 43 –
PARTS SIDE
SFR130
VC
FE
JW13
DIGITAL MULTIMETER
V
FE
VC
OUTPUT
EYE PATTERN
must be CLEAR and MAX
OSCILLOSCOPE
OUTPUT
RF
VC
DIGITAL MULTIMETER
V
R2
R2
1
1 2 3
Approx.
1.8Vp-p
0V
VOLT / DIV: 500mV
TIME / DIV: 0.2µs
JITTER METER
INPUT
ns