Fisher CA-272 - Page 4

DISASSEMBLY
INSTRUCTIONS
A.
REMOVAL
OF
FRONT
PANEL
4.
Remove
four
screws
(D)
fastening
Front
Panel
and
then,
pull
Front
Panel
toward
you.
(Fig.
3)
1.
Detach
Cover
by
removing
five
screws.
2.
Pull
out
TONE
CONTROL
Volume
knobs
(A).
(Fig.
1)
(D)
(D)
Fig. 3
Fig. 1
3.
Remove
three
screws
(B)
fastening
Front
Panel.
B.
REPAIR
AND
ADJUSTMENT
OF
PRINTED
(Fig.
2)
CIRCUIT
BOARD
1.
The
removal
of
Cabinet
Bottom
Cover
(C)
will
give
an
access
to
the
repair
or
adjustment
work
|
of
Main
Supply
Printed
Circuit
Board.
(Fig.
2)
(B)
(B)
Fig.
2
POWER
AMPLIFIER
ADJUSTMENT
BEFORE ADJUSTMENT
This
adjustment
is
very
sensitive
to
changes
in
ambient
temperature.
Allow
set
to
operate
for
10
mi-
nutes
before
attempting
this
adjustment.
IDLING CURRENT ADJUSTMENT
Set the SPEAKER switch to off position.
Turn VOLUME control to minimum.
Connect
DC
VTVM
between
TP13
and
TP15
on
the
Main
Amplifier
P.C.Board.
Adjust
VRO1
for
an
indication
of
7mV
(30mA)
on
the
DC
VTVM.
Connect
DC
VTVM
between
TP14
and
TP16
on
the
Main
Amplifier
P.C.Board.
Adjust
VRO2
for
an
indication
of
7mV
(30mA)
on
the
DC
VTVM.
ODO). Ne
aay