Aiwa XR-EM70 Service Manual page 38

<CD SECTION>
PWB CD
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: Oscilloscope (Use the probe of 10:1)
Test Disc:
1. Focus Offset Adjustment
1) Connect a digital multimeter to the test point (FE), (VC).
2) Play back the 2nd track of TCD-782.
3) Adjust SFR501 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.
R546
RIOP
SFR501 FE
IC651
Digital Multimeter (Use it in the DC Volt range)
Jitter meter (Kikusui 6235)
TCD-782
ATD-001
VC
TE
IC501
RF
OSCILLOSCOPE
RF
VC
RF
VC
– 38 –
6
1
4
2 3
DIGITAL MULTIMETER
FE
VC
OUTPUT
EYE PATTERN
must be CLEAR and MAX
OSCILLOSCOPE
JITTER METER
OUTPUT
INPUT
V
Approx.
±
1.8 0.3
Vp-p
0V
VOLT / DIV: 500mV
ns