CD-DP2400H (serv.man16). Troubleshooting - Sharp Audio Service Manual (repair manual)

– 42 –

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.

(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

Cleaner Liquid

Cleaning Disc

1. 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.

2. Place the CD cleaner disc onto the CD disc tray with the brush side down, then press the play button.
3. You will hear music for about 20 seconds and the CD player will automatically stop. If it continues to turn, press the stop button.

The CD lens cleaner should be effective for 30 - 50 operations, however if the brushes become worn out earlier then please
replace 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
rinse with clean water and seek medical advice.
The CD cleaner disc must not be used on car CD player or on computer CD ROM drives.
All rights reserved. Unauthorized duplicating, broadcasting and renting product is prohibited by law.

Parts code

1.

CD optical pickup Lens cleaner disc

UDSKA0004AFZZ

– 43 –

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

1. Is focus servo activated? (Waveform drawing 43-2)

 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 43-3)

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. Does 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 43-1).

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

µ

FDO

DRF

TE

Stopped

µ

µ

– 44 –

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 44-1 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 44-2)

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

2. The turntable doesn't rotate.

TE

DRF

Stopped

µ

FDO

SPDO

Stopped

µ

No

Yes

No

Yes

Yes

No

– 45 –

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 45-2).

If OK, check the unit.

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 45-1)

Check around pins 1~6 on IC2.

FDO

PDO2

PDO1

Stopped

µ

DOUT

Stopped

µ