Sharp CD-BA300 Service Manual page 44

CD-BA300
(4) PLL system check
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 44-1)
Check around pins 73~78 on IC1.
(5) Others
The HF waveform is normal and the time is displayed
normally, but no sound is produced. Or the sound
has dropouts.
Is pin 52 (C2F) on IC1 "L"?
1. When playing at normal speed
Check the peripheral circuit at pin 39 (DOUT) on IC1 and
the waveform (Figure 44-2).
If OK, Check the unit.
Yes
Stopped
CH1=500mV
DC 10:1
PDO1
3
4
PDO2
T
FDO
1
=Filter=
Smoothing : ON
BW : FULL
No
There are too many error flags on a damaged disc which
makes error correction impossible.
Check again using a known good disc.
Stopped
CH1=2V
DC 10:1
T
1
DOUT
=Filter=
Smoothing : ON
BW : FULL
– 44 –
1999/04/05 17:33:17
CH3=1V CH4=1V
DC 10:1 DC 10:1
=Offset= =Record Length=
CH1 : 0.000V Main : 100K Mode : AUTO
CH2 : 0.0V Zoom : 2K Type : EDGE CH2
CH3 : 0.00V Delay :
Hold off :
CH4 : 0.00V
Figure 44-1
T
1999/04/07 09:25:28
=Offset= =Record Length= =Trigger=
CH1 : 0.00V Main : 1K Mode : NORMAL
CH2 : 0.00V Zoom : 100 Type : EDGE CH1
CH3 : 0.00V Delay :
CH4 : 0.00V Hold off :
Figure 44-2
500ms/div
(500ms/div)
NORM:20kS/s
CH1
v/DIV
500mV
=Trigger=
0.0ns
0.2µs
500ns/div
(500ns/div)
NORM:200MS/s
2.887ms
0.2µs