Sharp CD-BP90W Service Manual page 44

CD-BK100W/CD-BP90W
(2) Tracking system check.
Check the TE waveform at pin 18 on IC1.
If the waveform shown in Figure 44-1 appears and soon after
NO DISC appears ?
"Initialization" is possible, but play is not possible ?
"Initialization" is not possible.
(3) Spin system check.
Press the OPEN/CLOSE switch without inserting a disc, and
then try starting the play operation.
1. The turntable rotates a little ?
(Waveform drawing Figure 44-2)
2. The turntable doesn't rotate.
No
No
No
The tracking servo is not activated.
Yes
Check the peripheral circuits at pins 18 and 19 on IC1, pin 16 on
IC2, and CNS1A/B.
A normal jump operation cannot be completed or the beginning of
Yes
the track cannot be found.
Check the around pin 23 on IC2.
Data cannot be read. Check the VCO-PLL system.
Stopped
CH1=10 V
DC 10:1
TE
2
DRF
T
1
=Filter=
Smoothing : ON
BW : FULL
The spin driver circuit is OK.
Yes
Check around pin 25 on IC2, pins 15 and 16 on IC3, and CNS3A/B.
Stopped
CH1=200 mV
DC 10:1
T
FDO
2
SPDO
1
=Filter=
Smoothing : ON
BW : FULL
– 44 –
T
CH2=1 V
DC 10:1
=Offset= =Record Length=
CH1 : 0.0 V Main : 100 K Mode : NORMAL
CH2 : 0.00 V Zoom : 2 K Type : EDGE CH1
CH3 : 0.00 V Delay :
Hold off :
CH4 : 0.00 V
Figure 44-1
T
1999/04/07 09:51:15
CH2=500 mV
DC 10:1
=Offset= =Record Length= =Trigger=
CH1 : 0.000 V Main : 100 K Mode : NORMAL
CH2 : 0.000 V Zoom : 2 K Type : EDGE CH2
CH3 : 0.00 V Delay :
Hold off :
CH4 : 0.00 V
Figure 44-2
100 ms/div
(100 ms/div)
NORM:100 kS/s
=Trigger=
2.924 ms
0.2 µs
500 ms/div
(500 ms/div)
NORM:20 kS/s
2.924 ms
0.2 µs