Sharp XL-HP515 Service Manual - Page 40

XL-HP515 (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. Stopped CH1=500 mV DC 10:1 T FDO 1 CH3=500 mV DC 10:1 500 ms/div (500 ms/div) NORM:20 kS/s TDO 3 =Filter= Smoothing : ON BW : FULL =Offset= CH1 : 0.000 V CH2 : 0.0 V CH3 : 0.000 V CH4 : 0.00 V CH1 v/DIV 500 mV =Record Length= Main : 100 K Zoom : 2 K =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) posi- No Sled motor (M2A). tion ? 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) Yes 2. Does DRF change from "L" to "H" ? Yes 3. Is the HF waveform normal ? (Waveform drawing Figure 3) Stopped CH1=500 mV DC 10:1 CH2=10 V DC 10:1 CH3=1 V DC 10:1 FDO 1 T 2 DRF No Pins 7~11, 79 and 80 on IC1 Check the laser diode driver Q1 peripheral circuit. 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. No If the level is not normal. 500 ms/div (500 ms/div) NORM:20 kS/s 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 : 2 K 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 Figure 2 7 - 2 Figure 3 Vp-p=1.0 V~1.3 V 0.5 mV/div,0.5 µsec/div