16. Voltage Measurements
17. Localizing Troubles
a. General. In the troubleshooting chart (c
a. Measure the tube socket voltage with the
below), procedures are outlined for isolating
troubles to a particular component part. Voltage
for voltages normally present.
that the switches and controls are set as indi-
ures 1113. Depending
on the nature
of the op-
erational symptoms, one or more of the localiz-
b. Measure the voltage at the test points on
ing procedures will be necessary.
b. Use of Chart. The troubleshooting chart is
the front, rear, and top of the chassis with the
designed to supplement operational checks that
cal voltages. Be sure that the switches and con-
can be performed at an organizational level. If
trols are set as indicated in the Notes column on
previous operational checks have resulted in
reference to a particular item of the chart, go
c. Measure the voltage at the test points on
directly to the referenced item. If no operational
the resistor mounting board (fig. 13) with the
symptoms are known, begin with step 1 of the
multi meter. Be sure that the switches and con-
equipment performance checklist (TM 116625
trols are set as indicated in the Notes column
31612) and proceed until a symptom of trou-
c. Troubleshooting Chart (fig. 26).
PILOT lamp 11 does not light and Fuse F1 or F2 defective or
Check fuses F1 and F2. Replace as
necessary. If replaced fuse burns
tube tester fails to operate.
out, check plate supply (terminals
pacitors C3 and C4 for short cir-
Check lamp 11 and replace if neces-
PILOT lamp 11 defective
Check power cord and connector
Power cord defective
and replace if necessary.
Check meter M1 and replace if
PILOT lamp 11 lights but FILA- F I L A M E N T VOLTS meter
MENT VOLTS meter M1 does
Filament transformer T1
Replace 1 if necessary.
FILAMENT RANGE switch Check switch S1. Replace switch S1
Check primary windings of trans-
PILOT lamp 11 lights but PLATE Power transformer T2 pri-
meter M5, SCREEN VOLTS
18b). Repair defective wiring or
meter M2, and SIGNAL meter
M4 do not indicate.
W i t h FUNCTION switch S4 in
Plate supply tube V1
TEST position and PLATE-
SCREEN RANGE switch S3 in
any position but OFF, PLATE ,
PLATE meter M5 defective-----
Check meter M5 and replace if
meter M5 indicates zero plate
P L A T E - S C R E E N R A N G E Check switch S3 and replace if
switch S3 defective.
Transformer T2 secondary
winding 314 open.
GRID BIAS VOLTS meter M2 does Bias supply tube V2 defective.
G R I D BIAS VOLTS meter Check meter M2 and replace if