Oki OKIFAX OF-38 Field Service Manual - page 168
of
284
5.1.4
NAK Tone Detection
Service personnel can adjust the NAK (Not Acknowledge) tone detection frequency
with a potentiometer.
The disassembly procedure to reveal the NCU-181 is described in sub-item 7.3.5 in
Chapter 7.
PC board name:
Measurement points:
Specification:
Required tool:
Measurement
NCU-181
pin and
pin
The
pin reading is 3240 Hz 10 Hz
RV4 (potentiometer)
.
Frequency
counter
Oscillator
Connect the leads of the frequency counter between the
pin and the
pin
(See Figure 5.1.4 at next page.)
b)
Connect the leads of the oscillator at line terminals and
c)
Turn on the AC power switch.
d)
Verify the specifications.
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