Sharp CD-C250X BK - Page 17

l Checking tke VCO-PLL system
1
Play operation is performed when disc exits.
Yes
Although HF waveform is normal,
Check PDO waveform (Fig. 17-1).
Error
Check the ICl pins 43 and 44, IC2 pins 3,5,7, 10, and 11.
Stop --> Play
1
As VCO freque-
ncy is locked at
0.5s
1 .oo v
IC2 @ PDO
0.5s
1 .oo v
ICI @ FD
4.32 M Hz,
voltage of PDO
rises and stabili-
zes.
Figure 17-l
l Although MF waveform is norm& ‘and the &me
indication is,normat, no.srrund is emRted.
Check IC 2
Yes
Usually, the number of pulses of flawless disc is 100 pulsesisec
Check IC2 pins 48, 49, 52, and 53 (Fig. 17-2,3).
Check the periphery of IC3 (OPAMP).
In STOP stat-
e CHP/CHN
clocks are the
same. and o-
utput is not
given. -~
0.2ps
2.00 v
RCHNiLCHN
Figure 17-2
0.2fJs
2.00 v
RCHPILCHP
0.2us
2.00 v
RCHN/LCHN
Due to diffe-
rence in wa-
veform of
CHP/CHN
(duty ratio)
in PLAY
mode output
is given.
Figure 17-3
-17-