Sharp CD-C471 W Service Manual page 42

CD-C471 W
l o a d e d
Is the Focus servo active? (Can you hear it working?)
Is HF waveform normal (see the Fig. 42-1, 2)?
Check the tracking system.
H i
(When playing
back the disc)
Figure 42-1
l
Check waveform of ICl pin 7 (TE).
The waveform shown in Fig.
state appears soon.
. '. . .
Yes
Yes
Yes
--
Tracking servo is
Yes ) inoperative.
Although IL is possible,
Yes
Check the laser diode driver.
No
Check the area around ICl(16) b (21) (focus servo circuit).
If the disc is not turning, the DRF
No
should not change to "H".
Waveform is unstable.
0.5s
ICI @ FD
0.55
10.0 v
ICI @ DRF
2.00 v
Check the VCO-PLL system.
Figure 42-3
Check the spin system.
Yes
Check the periphery of
Yes
Check the spin system.
Waveform in case of
normal play-back
Figure 42-2