Sharp CD-MPX880H Service Manual ▷ View online
CD-MPX880H
7 – 1
CHAPTER 7. FLOWCHART
[1] Troubleshooting
1. When the CD does not function
The CD section may not operate when the objective lens of the optical pickup is dirty. Clean the objective lens, and
check the playback operation. When this section does not operate even after the above step is taken, check the follow-
ing items.
check the playback operation. When this section does not operate even after the above step is taken, check the follow-
ing 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."
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.
2. When a CD cannot be played
2.1. Pressing the CD operation key is accepted, but playback does not occur.
1) Focus-HF system check
2) Tracking system check
3) Spin system check
4) PLL system check
Parts code
1.
CD optical pickup Lens cleaner disc
UDSKA0004AFZZ
HOW TO USE
CAUTION
Cleaning 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 still play continuously, 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 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 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 players or on computer CD-ROM
drives.
All rights reserved. Unauthorized duplicating, broadcasting and renting this product
is prohibited by law.
CD-MPX880H
7 – 2
Although a CD is inserted and the cover is closed,
"NO DISC" is displayed.
"NO DISC" is displayed.
(1) Focus-RF system check.
Press the Tray1 CD Eject Button without inserting a disc, and try
starting the playback operation.
starting the playback operation.
Figure 1
IC1
IC1
1
22
23
2
FDO
TDO
1. Does the pickup move to the PICKUP-IN Switch (NSW1)
position ?
position ?
No
Sled motor (NM2).
Yes
2. Does the focus (lens) move up and down ?
(Waveform drawing Figure 1)
(Waveform drawing Figure 1)
No
Check the focus peripheral circuit.
Yes
3. Is the laser lit ?
No
Check the laser diode driver Q1 peripheral circuit.
Yes
4. Is the turntable rotating ?
No
Spindle motor (NM1).
When a disc is loaded, start playback operation.
1. Is focus servo activated ?
(Waveform drawing Figure 2)
(Waveform drawing Figure 2)
No
Pins 5~9, 11, 18 19 and 22 on IC1
Check the laser diode driver Q1 peripheral circuit.
Check the laser diode driver Q1 peripheral circuit.
Yes
2. Is the RF waveform normal ?
(Waveform drawing Figure 3)
(Waveform drawing Figure 3)
No
If the level is not normal.
Figure 2
IC1
IC1
22
16
3
1
FDO
TE
Figure 3
IC1
2
RFOUT
4
CD-MPX880H
7 – 3
Check the TE waveform at pin 16 on IC1.
(2) Focus-RF system check.
If the waveform shown in Figure 4 appears and soon after NO
DISC appears ?
DISC appears ?
Yes
The tracking servo is not activated.
Check the peripheral circuits at pins 15, 16 and 23 on IC1,
and FFC1.
Check the peripheral circuits at pins 15, 16 and 23 on IC1,
and FFC1.
No
"Initialization" is possible, but play is not possible ?
Yes
A normal jump operation cannot be completed or the begin-
ning of the track cannot be found.
Check the around pin 23 on IC1.
ning of the track cannot be found.
Check the around pin 23 on IC1.
No
"Initialization" is not possible.
Data cannot be read. Check the VCO-PLL (Pin26~30 on IC1)
system.
system.
Figure 4
IC1
IC1
TE
16
RFOUT
2
3
4
(3) Spin system check.
Press the OPEN/CLOSE switch without inserting a disc, and
then try starting the play operation.
then try starting the play operation.
1. The turntable rotates a little ?
(Waveform drawing Figure 5)
(Waveform drawing Figure 5)
Yes
The spin driver circuit is OK.
No
2. The turntable doesn't rotate.
Check around pin 25 on IC1, pins 1 and 2 on CNP2.
Figure 5
IC1
IC1
22
25
5
1
FDO
SPDO
CD-MPX880H
7 – 4
(4) PLL system check.
When a disc is loaded, start play operation.
The RF waveform is normal, but the TOC data cannot be read.
Check the PDOUT waveform. (Figure 6)
Check around pins 26~30 on IC1.
Figure 6
IC1
IC1
IC1
28
22
27
1
7
6
PDOUT 1
PDOUT 0
FDO
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