Casio ZD-3 Service Manual page 22

Repair Item 2-B
Waveform
Is waveform at
pin 35 (RF) of IC702 like that
shown in figure 10 ?
Yes
Is pin 49(GFS) of of IC702
high ?
Yes
* Check pins 29, 30 and 31 of IC702.
* Check pins 17 and 49 of IC702.
* IC702 is defective.
Figure 10
All manuals and user guides at all-guides.com
B
Watch the waveforn at pin 31 (RFO) of
IC801 an oscilloscope.
No
No
Does 16.93 MHz appear
at pin 70 (XTAL) of IC702 ?
* Check circuit around and
soldering IC702.
* IC702 is defective.
0.9 Vp-p
~
1.1 Vp-p
20
* Check circuit around C and pin 35 of
IC702 (RF).
* IC702 is defective.
No
Yes
Waveform
C
* Check crystal and circuit
around it.
* IC702 is defective.