Electrical Adjustments; Ringing Signal Detection Sensitivity - Oki OKIFAX OF-38 Field Service Manual

C H A P T E R 5 .
5.1

Electrical Adjustments

5.1.1

Ringing Signal Detection Sensitivity

Service personnel can adjust the sensitivity to detect a ringing signal with a
potentiometer.
The disassembly procedure
Chapter 7.
. PC board name
- F r e q u e n c y [ H z ]
Measurement
Connect an oscilloscope probe between the IC5-5 pin and the IC5-1 pin.
(See Figure 5.1.1 at next page.)
Connect the leads of the ringing oscillator at line terminals Ll and L2.
Turn on the AC power switch.
c)
ADJUSTMENT
to reveal
the NCU-181 is described in to sub-item 7.3.5 in
is inpljt to the line terminals, and
is input to the line terminals.
5 - l