Sharp CD-BA1200H Service Manual page 40

CD-BA1200H
(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 40-1)
Check around pins 1~6 on IC2.
(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 35 (C2F) on IC2 "L"?
1. When playing at normal speed
Check the peripheral circuit at pin 37 (DOUT) on IC2 and
the waveform (Figure 40-2).
If both 1. and 2. are OK.
T
Stopped
CH1=2V
DC 10:1
T
1
DOUT
=Filter= =Offset=
Smoothing : ON CH1 : 0.00V
BW : FULL CH2 : 0.00V
CH3 : 0.00V
CH4 : 0.00V
Figure 40-2
Yes
1999/04/07 09:25:28
500ns/div
(500ns/div)
NORM:200MS/s
=Record Length= =Trigger=
Main : 1K Mode : NORMAL
Zoom : 100 Type : EDGE CH1
Delay : 2.887ms
Hold off : 0.2us
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.
– 40 –
1999/04/05 17:33:17
CH3=1V CH4=1V
DC 10:1 DC 10:1
=Offset= =Record Length= =Trigger=
CH1 : 0.000V Main : 100K Mode : AUTO
CH2 : 0.0V Zoom : 2K Type : EDGE CH2
Delay :
CH3 : 0.00V
CH4 : 0.00V Hold off :
Figure 40-1
500ms/div
(500ms/div)
NORM:20kS/s
CH1
v/DIV
500mV
0.0ns
0.2us