Casio ZD-1 Service Manual page 18

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