CD-DP2500 (serv.man23). Trouble shooting guide - Sharp Audio Service Manual (repair manual)

– 48 –

Parts code

1.

CD optical pickup Lens cleaner disc

UDSKA0004AFZZ

When the CD section does not operate when the objective lens of the optical pickup is dirty, this section may not operate. Clean
the objective lens, and check the playback operation. When this section does not operate even after the above step is taken, check
the following items.
Remove the cabinet and follow the trouble shooting instructions.
"Track skipping and/or no TOC (Table Of Contents) may be caused by build up of dust other foreign matter on the laser pickup
lens. Before attempting any adjustment make certain that the lens is clean. If not, clean it as mentioned below."

Turn the power off.
Gently clean the lens with a lens cleaning tissue and a small amount of isopropyl alcohol.
Do not touch the lens with the bare hand.

HOW TO USE

CAUTION

Cleaner Fluid

Cleaner disc

Using the brush in the cleaner cap, apply 1 or 2 drops of the cleaning fluid to the 

brush on the CD cleaner disc which has the mark next to it.

Place the CD cleaner disc onto the CD disc tray with the brush side down,then 

press the play button.

You will hear music for about 20 seconds and the CD player will automatically stop. 

If it continuous to tum, press the stop button.

1.

2.

3.

The CD lens cleaner should be effective for 30-50 operations, however if the 

brushes become worn out earlier then please the cleaner disc.

If the CD cleaner brushes become very wet then wipe off any excess fluid with a soft 

cloth.

Do not drink the cleaner fluid or allow it to come in contact with the eyes. In the 

event of this happening then drink and / or rines with clean water and seek medical 

advice.

The CD cleaner disk must not be used on car CD players or on computer CD ROM 

drives.

All rights reserved.Unauthorized duplicating, broadcasting and renting this product is 

(1) Check the power to IC2 (LC78641E), the presence of the clock signal (16.93 MHz) and the status of the RESET terminal
     (pin 71 on IC2).
(2) Did the pickup move to the PICKUP-IN Switch (SW4) position?

If (1) and (2)  are OK, check the system microcomputer (especially the communication line with the DSP).

(1) Focus-HF system check
(2) Tracking system check
(3) Spin system check
(4) PLL system check
(5) Others

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If the level is not normal, check around pins 27~29 on IC1.

1. Is focus servo activated? (Waveform drawing 49-2)

 Pins 1~11 on IC1
Check the laser diode driver Q3 peripheral circuit.
Focus error circuit (pins 20 and 21 on IC1)

When a disc is loaded, start playback operation.

2. Does DRF change from "L" to "H"?

Is the disc rotating?

3. Is the HF waveform normal?  (Waveform drawing 49-3)

Check the spin system.

If the disc is spinning and a HF waveform is generated,
DRF will go H.

Check the laser diode driver Q3 peripheral circuit.

1. Did the pickup move to the PICKUP-IN Switch (SW4)

position?

Sled motor (M2)

Press the OPEN/CLOSE switch (SW1) without inserting a
disc, and try starting the playback operation.

2. Does the focus (lens) move up and down?
    (Waveform drawing 49-1).

Check the focus peripheral circuit.

3. Is the laser lit?

Spindle motor (M1).

4. Is the turntable rotating?

Yes

Yes

Yes

No

No

No

No

No

No

No

Yes

Yes

No

FDO

TDO

Stopped

FDO

DRF

TE

Stopped

µ

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The tracking servo is not activated.
Check the peripheral circuits at pins 18 and 19 on IC1, pin 23 on
IC2, and CNS1A/B.

If the waveform shown in Figure 50-1 appears and soon after
NO DISC appears.

A normal jump operation cannot be completed or the beginning of
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.

Press the OPEN/CLOSE switch without inserting a disc, and
then try starting the play operation.

The spin driver circuit is OK.

1. The turntable rotates a little. (Waveform drawing 50-2)

Check around pin 25 on IC2, pins 15 and 16 on IC3, and CNS3A/B.

2. The turntable doesn't rotate.

TE

DRF

Stopped

FDO

SPDO

Stopped

No

Yes

No

Yes

Yes

No

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Is pin 35 (C2F) on IC2 "L"?

Yes

No

There are too many error flags on a damaged disc which
makes error correction impossible.

Check again using a known good disc.

1. When playing at normal speed

Check the peripheral circuit at pin 37 (DOUT) on IC2 and
the waveform (Figure 51-2).

If both 1. and 2. are OK.

When a disc is loaded, start play operation.

The HF waveform is normal, but the TOC data cannot be
read.

Check the PDO waveform. (Figure 51-1)

Check around pins 1~6 on IC2.

FDO

PDO2

PDO1

Stopped

DOUT

Stopped