MD-M3/M1
– 60 –
Is pin 35 (C2F) on IC2 "L"?
Yes
No
The HF waveform is normal and the time is displayed
normally, but no sound is produced. Or the sound has
dropouts.
(5) Others
There are too many error flags on a damaged disc which
makes error correction impossible.
Check again using a known good disc.
1. When playing at normal speed
Check the peripheral circuit at pin 37 (DOUT) on IC2 and
the waveform (Figure 60-2).
2. When recording at double speed
Check the peripheral circuit at pins 57~59 (DATA, DATACK,
LRSY) on IC2 and the waveform (Figure 60-3).
If both 1. and 2. are OK, check the MD unit.
When a disc is loaded, start play operation.
(4) PLL system check
The HF waveform is normal, but the TOC data cannot be
read.
Check the PDO waveform. (Figure 60-1)
Check around pins 1~6 on IC2.
T
FDO
PDO2
PDO1
Stopped
CH1=500mV
DC 10:1
CH3=1V
DC 10:1
CH4=1V
DC 10:1
500ms/div
(500ms/div)
NORM:20kS/s
1
4
3
=Record Length=
Smoothing : ON
CH1 : 0.000V
CH2 : 0.0V
Main : 100K
Zoom : 2K
Mode : AUTO
Type : EDGE CH2
Delay : 0.0ns
Hold off : 0.2us
CH3 : 0.00V
CH4 : 0.00V
BW : FULL
=Trigger=
=Filter=
=Offset=
CH1
v/DIV
500mV
1999/04/05 17:33:17
Figure 60-1
T
T
DOUT
Stopped
CH1=2V
DC 10:1
500ns/div
1999/04/07 09:25:28
(500ns/div)
NORM:200MS/s
1
=Record Length=
Smoothing : ON
CH1 : 0.00V
CH2 : 0.00V
Main : 1K
Zoom : 100
Mode : NORMAL
Type : EDGE CH1
Delay : 2.887ms
Hold off : 0.2us
CH3 : 0.00V
CH4 : 0.00V
BW : FULL
=Trigger=
=Filter=
=Offset=
T
T
DATA
DATACK
LRSY
Stopped
CH1=2V
DC 10:1
CH2=2V
DC 10:1
CH3=2V
DC 10:1
5us/div
(5us/div)
NORM:100kS/s
1
2
3
=Record Length=
Smoothing : ON
CH1 : 0.00V
CH2 : 0.00V
Main : 5K
Zoom : 100
Mode : AUTO
Type : EDGE CH3
Delay : 0.0ns
Hold off : 0.2us
CH3 : 0.00V
CH4 : 0.00V
BW : FULL
=Trigger=
=Filter=
=Offset=
CH3
v/DIV
2 V
1999/04/05 20:50:17
Figure 60-2
Figure 60-3
Содержание CP-M1
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