SD-EX100H (serv.man17). CD lens cleaning Troubleshooting - Sharp Audio Service Manual (repair manual). Page 4

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No

Yes

Does the disc motor rotate in CD test mode 3?

When changing CD test
mode from 2 to 3, is voltage
applied to the line between
Pins 5 and 6 of IC703 for
approx. 0.3 to 1.5 seconds?

The disc motor defective
or disconnected

Yes

When changing CD test
mode from 2 to 3, is high
voltage applied to Pin 41 of
IC702 for approx. 0.3 to 1.5
seconds and then does it
become pulse?

No

Is rotation excessively high or low?

IC702 defective or disconnected

• Recheck if objective lens of optical pickup is contaminated.
  If contaminated, clean the lens.
• Check connection of the line between IC701 Pin 19 and IC702 Pin
24. If OK, optical pickup is defective.

Are eye patterns generated in IC701 Pin 19?
 (See Waveform Figure 7 at P60.  Waveforms that are not clear
are acceptable.)

No

Yes

Are eye patterns Vp-p 1.2 V input to IC702 Pin 24?

Check PWB patterns and C756.

Yes

No

IC702 defective (Check peripheral components to replace.)

Yes

IC702 defective

No

Yes

 (Waveforms of Vp-p approx. 1.2 V)

0.3 to 1.5 seconds

0.3 to 1.5 seconds

5V

Check the periphery of IC702.  If OK, IC702 is defective.

No

Yes

Are digital signals output from IC702 Pin 4 (Digital OUT)?

Check the periphery of IC703.  If OK, IC703 is defective.

No

Are digital signals output from IC703  Pin 8 (Digital OUT)?

Check connection of CD and IC904.

No

Are digital signals output to IC900 Pin 16?

Yes

CNW901 Pin 1 and  Pin 3 waveform.

Yes

OK

Yes

Check IC900 and IC901.

No