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siete ieee
5,
Check the values of the component parts.
Be
sure
that
the
proper
part
has
been
wired
into the
circuit,
as
shown
in the
pictorial diagrams
and as called out in the
wiring instructions,
7,
If, after careful checks, the trouble is still
not
located
and a voltmeter
is available,
check voltage readings against those found
on
the
Schematic
Diagram.
NOTE:
All
voltage readings were taken with an 11 meg-
ohm input vacuum tube voltmeter, Voltages
may vary as much as 10% due to line volt-
age variations,
A
review
of the Circuit Description
will
prove
helpful
in indicating where
to look
for trouble,
SPECIFIC PROBLEMS
PROBLEM
CHECK
.
Filaments do not
light.
Filaments light, but
no sound with VOLUME
control turned fully
clockwise,
Check filament
wiring on top of the circuit
board
against
Pictorial
2
on
Page 33.
Open
tube
filament
- with an ohmmeter,
check for continuity between pins 3 and 4
on all four tubes,
Check
wiring
of terminal
strip J against
Pictorial 1 (fold-out from
Page 6),
Check
power
transformer
wiring against
Pictorial 1 (fold-out from
Page 6),
Make
sure
the
Selector
Switch is not in
STBY position,
Check
wiring
between the VOLUME
con-
trol
and
the
circuit
board
against
Pic-
torial 1 (fold-out from
Page 6),
CAUTION:
When
making the following checks,
do not touch the chassis with your
other hand,
Turn
the
Receiver
on and place a small
screwdriver on lug 5 of tube socket V4, then
touch
your finger to the metal portion
of
the screwdriver;
a low pitched hum should
be audible,
Now place the screwdriver on lug 1 of tube
socket V3, Again touch your finger to the
metal portion, this time the hum should be
louder,
If no hum is present check the circuit board
components
of tubes
V3
and
V4 and the
wiring to the speaker.
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