SHARP CDC821W
Instrukcja Serwisowa

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. Tracking servo is inoperative. Yes Check the periphery of IC 1 pin 8 to pin 15, and IC 5 to CNP2.

Yes

Play is possible in TEST mode.

Yes

The unit will be initialized in Normal mode,but it will not playback..

Yes

Normal jump is impeded, and the program top cannot be reached.
5ms 1.00 V IC1 7 TE

Yes

Check the periphery of IC 1 pin 14.

Data cannot be read. Yes

Check the VCO-PLL system.

4

5 ms 5.0 V IC1 54 DRF

3

Figure 44-1 � Checking the spin system.
Play operation is performed without disc.

The turntable rotates a little. No The turntable fails to rotate or rotates at high speed.

Yes

The spin driver circuit is normal.

Yes

Check the periphery of IC1 pins 23 to 27, pin 39, and pin 40, IC2 pin 12 and pin 13, IC3 to CNP3.

� Checking the VCO-PLL system
Play operation is performed when disc exits. Yes Although HF waveform is normal, TOC data cannot be read. Yes Check PDO waveform (Fig. 44-2). Abnormal Check the IC1 pins 43 and 44, IC2 pins 3, 5, 7, 10, and 11.
Stop --> Play As VCO frequency is locked at 4.32 MHz, voltage of PDO rises and stabilizes. 2

0.5s 1.00 V IC2 3 PDO 0.5s 1.00 V IC1 16 FD

3

� 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 IC401 and POWER AMP. IC601. No

Figure 44-2

Usually, the number of pulses of flawless disc is 100 pulses/sec or less.

� 44 �