Sharp CD-C811W Service Manual page 44

CD-C811W/821W
• Check the tracking system.
Check waveform of IC1 pin 7 (TE).
The waveform shown in Fig.
44-1 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.
The turntable rotates a little.
The turntable fails to rotate or rotates at high speed.
• Checking the VCO-PLL system
Play operation is performed when disc exits.
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).
Check IC2 pins 37, 40.
Check IC401 and POWER AMP. IC601.
Tracking servo is
inoperative.
Yes
The unit will be initialized
Yes
in Normal mode,but it will
not playback..
Check the VCO-PLL system.
Yes
No
Yes
Yes
Abnomal
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
The spin driver circuit is normal.
Yes
Check the periphery of IC1 pins 23 to 27, pin 39, and pin 40, IC2
Yes pin 12 and pin 13, IC3 to CNP3.
Check PDO waveform (Fig. 44-2).
Yes
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
Usually, the number of pulses of flawless disc is 100 pulses/sec
No or less.
– 44 –
Check the periphery
Yes
of IC 1 pin 14.
Figure 44-1
Stop --> Play
As VCO frequency
is locked at 4.32 MHz,
voltage of PDO rises and
stabilizes.
2
3
Figure 44-2
4
3