Casio ABX-68B, Repair Manual, Page: 15 / 52

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(+) Side, Gain <----- ACCURACY (Sec./ Day) -----> (–) Side, Lose
G1 Open (Close) (Open) (Close) Open (Close) Open Close
G2 Open (Open) (Close) (Close) Open (Open) Close Close
G3 Open (Open) (Open) (Open) Close (Close) Close Close
Notes: "Close" means the lead wire is connected (or soldered).
"Open" means the lead wire is cut (or not soldered).
4-2 Accuracy Setting by Pad Selection
The capacitance of the capacitor in the LSI can be
changed to nine different levels by combining the
open and shorted states of pads G1-G3 of the PCB
ass’y. (Fig. 4-3)
These changes in capacitance can be used to ad-
just the accuracy.
The combinations of these pads are as shown in
the following chart.
Although they can be adjusted during repairs, since
it is necessary to disassemble and reassemble the
module each time the rate is adjusted, this proce-
dure is actually quite difficult.
Thus, in the case a watch no longer runs accurately
or a oscillator/quartz has been damaged in modules for which accuracy setting is performed in this
manner, it is preferable that repairs are performed by replacement of the PCB ass’y or module.
4-3 Digital Tuning (Pattern Cutting) Method
This method is used for analog watches
(and mainly those of the two hand type).
Even if the oscillation frequency is not
32,768 Hz, a constant accuracy is main-
tained by adjusting the alternating current
signals that forcibly enter the coil. That
adjustment procedure is performed by
cutting lead wires (3-5) on the P.C.B. (Fig.
4-4)
The combination of cuts are also varies
according to the oscillator/quartz.
Thus, in the case the oscillator/quartz has
been damaged in a module in which this
rate setting method is employed, replace-
ment must be performed from the PCB ass’y or module.
Furthermore, when checking the accuracy with a quartz timer, checking should be performed at
a gate time of 10 seconds.
Fig. 4-4
Fig. 4-3
Oscillator/Quartz
Oscillator/Quartz