SHARP XLHP434H
Manual de Servicio

XL-HP434H
(1) Focus-HF system check. Although a CD is inserted and the cover is closed, "NO DISC" is displayed.
Press the Tray1 CD Eject Button without inserting a disc, and try starting the playback operation.
T

Stopped CH1=500 mV DC 10:1

CH3=500 mV DC 10:1

500 ms/div (500 ms/div) NORM:20 kS/s

FDO
1

TDO
3

CH1 v/DIV 500 mV =Filter= Smoothing : ON BW : FULL =Offset= CH1 : 0.000 V CH2 : 0.0 V CH3 : 0.000 V CH4 : 0.00 V =Record Length= Main : 100 K Zoom : 2K =Trigger= Mode : AUTO Type : EDGE CH1 Delay : 0.0 ns Hold off : 0.2 µs

Figure 1 1. Does the pickup move to the PICKUP-IN Switch (SW1A) position? No Sled motor (M2A).

Yes 2. Does the focus (lens) move up and down? (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)

No

Pins 7~11, 13,19 and 20 on IC1 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. If the disc is spinning and a HF waveform is generated, DRF will go H.

Yes 3. Is the HF waveform normal? (Waveform drawing Figure 3) No If the level is not normal.

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

FDO
1

T 2

DRF

TE
3

CH Position To -3 div -1 div 0 div +1 div +3 div =Filter= =Offset= =Record Length= Smoothing : ON CH1 : 0.000 V Main : 100 K BW : FULL CH2 : 0.0 V Zoom : 2K CH3 : 0.00 V CH4 : 0.00 V

CH2 Position 0.20 div =Trigger= Mode : AUTO Type : EDGE CH1 Delay : 0.0 ns Hold off : 0.2 µs

Vp-p=1.0 V~1.3 V 0.5 mV/div,0.5 µsec/div

Figure 2

Figure 3

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