Casio ZD-1

1. “CD OPEN” is not displayed.
16
1
Is +5 V lines pin 72
of IC704 normal ?
No
Yes
* Check IC705.
* Check circuit around IC705.
Is the waveform
at pin 30 of IC704 like that
shown in Fig. 12 ?
No
Yes
* Check Q713.
* Check circuit around IC706.
Does 16 MHz
clock pulse appear at
pin 31of IC704 ?
No
Yes
* Check X703.
* Check circuit around X703.
* Check IC704.
* Check circuit around IC704.
* Check soldering CN705 and FFC.
Figure 12
5 V
Power on
100 mS