Read Sharp CD-BA1700 (serv.man9) Service Manual online
CD-BA160H/1700H
– 42 –
The tracking servo is not activated.
Check the peripheral circuits at pins 18 and 19 on IC1, pin 23 on
IC2, and CNS1A/B.
Check the peripheral circuits at pins 18 and 19 on IC1, pin 23 on
IC2, and CNS1A/B.
If the waveform shown in Figure 42-1 appears and soon after
NO DISC appears.
NO DISC appears.
(2) Tracking system check
Check the TE waveform at pin 18 on IC1.
A normal jump operation cannot be completed or the beginning of
the track cannot be found.
Check the around pin 23 on IC2.
the track cannot be found.
Check the around pin 23 on IC2.
"Initialization" is possible, but play is not possible.
Data cannot be read. Check the VCO-PLL system.
"Initialization" is not possible.
Figure 42-1
Figure 42-2
Press the OPEN/CLOSE switch without inserting a disc, and
then try starting the play operation.
then try starting the play operation.
(3) Spin system check
The spin driver circuit is OK.
1. The turntable rotates a little. (Waveform drawing 42-2)
Check around pin 25 on IC2, pins 15 and 16 on IC3, and CNS3A/B.
2. The turntable doesn't rotate.
T
T
TE
DRF
Stopped
CH1=10V
DC 10:1
CH2=1V
DC 10:1
100ms/div
(100ms/div)
NORM:100kS/s
2
1
=Record Length=
Smoothing : ON
CH1 : 0.0V
CH2 : 0.00V
CH2 : 0.00V
Main : 100K
Zoom : 2K
Zoom : 2K
Mode : NORMAL
Type : EDGE CH1
Delay : 2.924ms
Hold off : 0.2us
Type : EDGE CH1
Delay : 2.924ms
Hold off : 0.2us
CH3 : 0.00V
CH4 : 0.00V
CH4 : 0.00V
BW : FULL
=Trigger=
=Filter=
=Offset=
T
T
FDO
SPDO
Stopped
CH1=200mV
DC 10:1
CH2=500mV
DC 10:1
500ms/div
1999/04/07 09:51:15
(500ms/div)
NORM:20kS/s
2
1
=Record Length=
Smoothing : ON
CH1 : 0.000V
CH2 : 0.000V
CH2 : 0.000V
Main : 100K
Zoom : 2K
Zoom : 2K
Mode : NORMAL
Type : EDGE CH2
Delay : 2.924ms
Hold off : 0.2us
Type : EDGE CH2
Delay : 2.924ms
Hold off : 0.2us
CH3 : 0.00V
CH4 : 0.00V
CH4 : 0.00V
BW : FULL
=Trigger=
=Filter=
=Offset=
Yes
No
Yes
No
Yes
No
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