Sharp GX-CD30 Service Manual page 11

• Playback can only be performed when a disc
is loaded.
Is the Focus servo active? (Can you hear it working?)
Does the DRF signal change from "L" to "H"?
Is HF waveform normal (see the Fig.11-1, 2)?
Check the tracking system.
HF
0.1V/DIV
0.5µsec/DIV(DC)
(When playing
back the disc)
• Check the tracking system.
Check waveform of IC801 pin 7 (TE).
Play is possible in
TEST mode.
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Yes
Yes
Yes
Figure 11-1
The waveform shown in Fig. 11-3
appears, and no-disc state appears
soon.
Although IL is possible,
Yes
play is impossible.
Data cannot be read.
5ms
1.00 V
IC801 7 TE
5 ms
5.0 V
IC801 54 DRF
manuals search engine
Check the laser diode driver.
Check the area around IC801(16) - (21) (focus servo circuit).
No
If the disc is not turning, the DRF
No should not change to "H".
No
evel is abnormal.
L
Waveform is unstable.
0.5s
1.00 V
IC801 16 FD
0.5s
10.0 V
IC801 12 CLV+
0.5s
10.0 V
IC801 54 DRF
0.5s
2.00 V
IC801 7 TE
Tracking servo is inoperative.
Yes
Normal jump is impeded, and the
program top cannot be reached.
Yes
Check the VCO-PLL system.
Yes
Figure 11-3
– 11 –
GX-CD30/30C/130/130C
Yes
Check the spin
system.
Yes
Check the periphery
of IC801 pins 41 and
42.
Yes
Check the spin
system.
2
1
3
4
Figure 11-2
Check the periphery of IC801
Yes
pin 8 to pin 15, and IC804 to
BI801/CNS801.
Check the periphery of
IC801 pin 14.
Yes
4
3
Waveform in case
of normal play-
back