Sharp CD-C602 Service Manual page 32

CD-C602,CP-C602
• Check the tracking system.
Check waveform of IC1 pin 7 (TE).
The waveform shown in Fig.
32-1 appears, and no-disc
state appears soon.
Play is possible in
TEST mode.
Data cannot be read.
• Checking the spin system.
Play operation is performed without disc.
Yes
The turntable rotates a little.
No
The turntable fails to rotate or rotates at high speed.
• Checking the VCO-PLL system
Play operation is performed when disc exits.
Yes
Although HF waveform is normal, TOC data cannot be read.
• Although HF waveform is normal and the time
indication is normal, no sound is emitted.
Check IC2 pin 48 (EFLG).
Yes
Check IC2 pins 37, 40.
Abnomal
Check IC431 and POWER AMP. IC601.
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Tracking servo is
inoperative.
Yes
Although IL is possible,
Yes
play is impossible.
Check the VCO-PLL system.
Yes
Yes
Yes
Yes
No
– 32 –
Check the periphery of IC 1
pin 8 to pin 15, and IC 5 to
Yes
CNP2.
Normal jump is impeded,
Yes
and the program top
cannot be reached.
5ms
1.00 V
IC1 7 TE
5 ms
5.0 V
IC1 54 DRF
Figure 32-1
The spin driver circuit is normal.
Check the periphery of IC1 pins 23 to 27, pin 39, and pin 40, IC2
pin 12 and pin 13, IC5 to CNP3.
Check PDO waveform (Fig. 32-2).
Abnormal
Check the IC1 pins 43 and 44, IC2 pins 3, 5, 7, 10, and 11.
0.5s
1.00 V
IC2 3 PDO
0.5s
1.00 V
IC1 16 FD
Figure 32-2
Usually, the number of pulses of flawless disc is 100 pulses/sec
or less.
Check the periphery
Yes
of IC 1 pin 14.
4
3
Stop --> Play
As VCO frequency
is locked at 4.32 MHz,
voltage of PDO rises and
stabilizes.
2
3