Lafayette TE-50 - Page 8

CAUSE:
SYMPTOM:
CAUSE:
SYMPTOM:
CAUSE:
SYMPTOM:
CAUSE
:
SYMPTOM:
CAUSE:
SYMPTOM:
CAUSE:
SYMPTOM:
Same as previous symptom. Knob on filament switch may have shifted.
Tester indicates “short” on good tubes when any one of the elemental switches is
moved to the “P” position.
A shorted 0.01 „fd capacitor will cause a false short indication on all positions.
Tester indicates “short” on some tubes but not on others. All tubes are known to
be good.
Due to incorrect operation. The element listed in the “P” column of the tube chart
is placed in the “P” position for quality tests only. It should te returned to the “K”
position before proceeding with the short test. Never place more than one switch
in the “P” position at any one time.
Tester indicates “short” when one of the switches is set to “P”. This occurs on all
tubes tested.
Tubes are not shorted. The elemental switch which causes the indicator to light is
the one listed under the “Fil. Cont.” column of the tube chart. This indicates filament
continuity
and
not
a
short.
Tester
shows
all
tubes
to
be
good,
even
though
they
are
weak.
The load control and/or 470 ohm resistor may have been burnt out. (See note
following.)
Note: The load control must be set according to the tube chart for quality tests.
It should never be turned to zero during the quality test, otherwise damage to the
control
and
tube
will
result.
Tester will not indicate “short” or filament continuity.
Trouble is usually caused by an open-circuit 0.01 pfd capacitor or defective neon
lamp.
Tube
tests
good
in
the
tester
but
will
not
operate
satisfactorily
in
the
radio
or
TV
receiver.