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MF-47L/ML
Outline of Selection Circuit
Pre-set
electronic
selection
system
is
adopted.
This
circuit consists of the following 4 part.
1.
2.
3.
Operation part.
Selection
part
which
drives
tuner
after
keeping
the
touch-input signal in memory.
Indicator
part which
indicates
the
FM
broadcast
in
receiving.
Pre-set
part
to
select
the
desired
FM
broadcasting
station previously.
Operation part
There are two kinds of the operation system:
senser system and switch system. Model FM-47ML
uses
senser
system
of
2-pole
type.
(To
touch
2 poles
simultaniously.)
Selection part
In this part, the touch
input signal is kept in memory,
and pre-set voltage is given to the tuner driving circuit,
and also the output for indication of FM station is given
to the indicator circuit.
This part utilizes two
pieces of IC (uPC 1009C)
of
senser type which electronically select a station.
Indicator part
LED
is used
as for
indicator
of the
FM
station
in
receiving.
The
output
for indicator
coming
from
the
selection
part
makes
transistor
switch
to
lighten
L.E.D.
Pre-set part
This part consists of 7 variable resistors for pre-setting.
Trouble shooting chart of FM pre-set.
All pre-set LED do not light.
(Defective) —>
U
VES
( D e f e c t
Is the Function switch set at '""FM''?
NO ———
Set at ''FM"" position.
Pre-set L.E.D does not shift.
Is the sensor concerned with light-
ing L.E.D wet or dusty?
Remedy
Is'nt your finger too dry?
Are'nt you physically
touching on moistened
floor or an object which
functions as an earth?
(ex. The fitting has earth
function.)
Is the +B1 & B2
voltage normal?
YES
——~ Check
pre-set circuit board.
NO ——~>Check power source circuit.
YES Wp
e thee dust or moisture enough.
1
Moisten your finger and try it.
YES—>
2
Put on slippers.
Keep your hand off the earth
object.
Tuning is slipping off though
Pre-setting was once made.
Does not change room temperature
greatly?
YES
Re-adjustment is needed.
NO
Is'nt the tuning knob operated?
NO ——_»
Check the pre-set or tuner
circuit board.
Caution:
In case dusty oil was stuck on the pre-set circuit board, receiving frequency may vary from one of pre-set state.
No. 7011
Please be mind on this point when servicing.
NO ———
Check the pre-set circuit board.
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