Waveforms Of Cd Circuit - Sharp MD-R3 Service Manual

,
1 2
IC700
100
2V/1mS (DC range)
90
[Disc playback mode]
Potential difference 0V
Disc free from flaw
10
0%
Disc having flaw
(the same as above) 100
90
Potential difference 0V
If a flaw exists, pulse-like
noise appears as shown
right.
10
Noise appears also in
0%
output of and TE or
FE signal.
,
IC700 11 12
100
0.5V/0.5mS
90
(Dc range)
[Disc playback mode]
Potential difference 0V
10
0%
9
IC750
100
50mV/2mS
90
[Disc playback mode]
1/2VCC
10
0%
3
TP751
100
0.2V/0.5 S
90
(AC range)
[Disc playback mode]
10
0%
4
TP751
100
0.2V/1mS
90
(DC range)
In test mode 3
1/2VCC
10
0%

WAVEFORMS OF CD CIRCUIT

– 59 –
0.2V/1mS (DC range)
100
[Disc playback mode]
90
1/2VCC
10
0%
IC750 22
100
90
In test mode 2
(disc is not loaded.
Lens is moved up and down.)
1/2VCC
200mV/0.5S (DC range)
* Observation with the aid
10
of storage oscilloscope
0%
Only the triangular wave
and luminous dot shown
right are observed on oscillograph.
,
IC800 37 38
100
Disc motor
90
PWM output PWM1
0.2V/10 S
(DC range)
GND
[Disc playback mode]
(Use the 10:1
PWM2
probe.)
10
0%
GND
IC800 19
100
20mV/0.5 S
90
(AC range)
[Disc playback mode]
(Use the 10:1 probe.)
10
0%
IC800 28
100
2V/0.1 S (DC range)
90
[Disc playback mode]
GND
10
0%
* If disc has flaw or during track
search pulse-like "L" level appears
4
as shown below.
IC800
2Vdiv (DC range)
100
Playback mode, 4.8V
90
Stop mode, 0V
When the disc rotates and
the HF signal is
synchronized with the IC
10
0%
internal signal, H level is
set.
MD-R3
TRIG