Read Sharp XL-HP404 (serv.man10) Service Manual online
XL-HP404E/HP404H
7 – 2
Although a CD is inserted and the cover is closed, "NO
DISC" is displayed.
DISC" is displayed.
(1) Focus-HF system check.
Press the Tray1 CD Eject Button without inserting a disc, and try
starting the playback operation.
starting the playback operation.
Figure 1
T
FDO
TDO
Stopped
CH1=500 mV
DC 10:1
CH3=500 mV
DC 10:1
500 ms/div
(500 ms/div)
NORM:20 kS/s
1
3
=Record Length=
Smoothing : ON
CH1 :
0.000 V
CH2 :
0.0 V
Main :
100 K
Zoom :
2 K
Mode : AUTO
Type : EDGE CH1
Delay :
Type : EDGE CH1
Delay :
0.0 ns
Hold off :
0.2 µs
CH3 :
0.000 V
CH4 :
0.00 V
BW : FULL
=Trigger=
=Filter=
=Offset=
CH1
v/DIV
500 mV
500 mV
1. Does the pickup move to the PICKUP-IN Switch (SW1A) posi-
tion?
tion?
No
Sled motor (M2A).
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 (M1A).
When a disc is loaded, start playback operation.
1. Is focus servo activated?
(Waveform drawing Figure 2)
(Waveform drawing Figure 2)
No
Pins 7~11, 13,19 and 20 on IC1
Check the laser diode driver Q1 peripheral circuit.
Check the laser diode driver Q1 peripheral circuit.
Yes
2. Does DRF change from "L" to "H"?
No
Is the disc rotating?
No
Check the spin system.
Yes
If the disc is spinning and a HF waveform
is generated, DRF will go H.
is generated, DRF will go H.
3. Is the HF waveform normal?
(Waveform drawing Figure 3)
(Waveform drawing Figure 3)
No
If the level is not normal.
Figure 2
T
FDO
DRF
TE
Stopped
CH1=500 mV
DC 10:1
CH2=10 V
DC 10:1
CH3=1 V
DC 10:1
500 ms/div
(500 ms/div)
NORM:20 kS/s
1
2
3
=Record Length=
Smoothing : ON
CH1 :
0.000 V
CH2 :
0.0 V
Main :
100 K
Zoom :
2 K
Mode : AUTO
Type : EDGE CH1
Delay :
Type : EDGE CH1
Delay :
0.0 ns
Hold off :
0.2 µs
CH3 :
0.00 V
CH4 :
0.00 V
BW : FULL
=Trigger=
=Filter=
=Offset=
-3 div
-1 div
0 div
+1 div
+3 div
CH Position To
CH2
Position
0.20 div
0.20 div
Figure 3
Vp-p=1.0 V~1.3 V
0.5 mV/div,0.5 µsec/div
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