TM 11-6625-2709-40
2-8. Troubleshooting Chart - Continued
Probable trouble
Proper
for improper
indication
Correction
Procedure
Indication
Step
44
Connect the equipment
The following lamps should
light:
as shown in figure 4-6.
a. Measure the dc voltage at the
a. If LOC PWR and GS PWR lamps
Set the megahertz and
a. LOC PWR and GS PWR
on aid box.
on aid box do not light, either a
test point located at the center
kilohertz selectors on the
of the GS 1A fuse cap. If 27.5
control unit to 108.00
break in the circuit is present be-
volts dc is not present, replace
tween P5-T and P7-Z, switch S6A
MHz. Set the test set
fuse F3. If a break in the circuit
in the control unit is defective, or
IND TEST switch to
is present between P5-T and
GS 1A fuse (F3) is blown on the
RCVR GS, AUDIO to
test set.
P7-Z, make resistance measure-
MB, and FLAG LOAD
ments to find the break. If no
to 5. Set the control unit
breaks are present, trou-
power switch to PWR.
bleshoot the control unit as de-
scribed in TM 11-5826-
226-34.
b. If VOR/LOC DC lamp on test set
b. Replace DS10.
b. VOR/LOC DC lamp on
does not light, DS10 is faulty.
test set.
c. If 26 VAC PWR lamp on aid box
c. Measure the ac voltage at test
c. 26 VAC PWR lamp on
point located at the center of the
does not light, VOR/LOC 1A fuse
aid box.
VOR/LOC 1A fuse cap. If 115
is blown, relay K1 is defective, or
volts ac is not present, replace
transformer T1 is defective.
fuse F1. If 115 volts sc is still
not present, check for a defec-
tive relay K1 by measuring its
coil resistance (para 2-9). If
defective, replace K1. Check for
a defective transformer by
measuring its resistances (para
2-9). Replace if defective.
d. If VOR/LOC AC lamp on test set
d. Replace DS9.
d. VOR/LOC AC lamp on
does not lit, DS9 is faulty.
tesl set.
e. Replace DS11.
e. If GS DC lamp on test set does not
e. GS DC lamp on test set.
light, GS DC tamp (DS11) is
burned out.
f. If 1.0 FREQ SELECT (MHz)
f. 1.0 FREQ SELECT
f. If a break in the circuit is pres-
lamp A does not light, either a
(MHz) lamp A on aid
ent, make resistance measure-
break in the circuit is present be-
ments to find the break. If no
box.
tween P7-G and P5-N or the
break is present, troubleshoot
megahertz selector in the control
the control unit as described in
unit is defective.
TM 11-5826-266-34.
g. If 1.0 FREQ SELECT (MHz)
g. If a break in the circuit is pres-
g. 1.0 FREQ SELECT
lamp D does not light, either a
ent, make resistance measure-
(MHz) lamp D on aid
ments to find the break. If no
break in the circuit is present be-
box.
tween P7-K and P5-T, or the
break is present, troubleshoot
the control unit as described in
megahertz selector in the control
unit is defective.
TM 11-5826-226-34.
h. If a break in the circuit is pres-
h. If 0.1 FREQ SELECT (MHz)
h. 0.1 FREQ SELECT
ent, make resistance measure-
tamp B does not tight, either a
(MHz)lamp B on aid
ments to find the break. If no
break in the circuit is present be-
box.
break is present, troubleshoot
tween P7-N and P5-J, or the
the control unit as described in
kilohertz selector in the control
TM 11-5826-226-34.
unit is defective.
i. If a break in the circuit is pres-
i. If 0.1 PREQ SELECT (MHz)
i. 0.1 FREQ SELECT
ent, make resistance measure-
lamp E does not light, either a
(MHz) lamp E on aid
ments to find the break. If no
break in the circuit is present be-
box.
break is present, troubleshoot
tween P7-S and P5-N, or the
the control unit as described in
kilohertz selector in the control
TM 11-5826-226-34.
unit is defective.
j. Refer to figure 4-12 and make
j. If FLAG meter does not indicate
j. FLAG meter should indi-
250 15.0 microamperes, switch
continuity checks on the circuit
cate 250 15.0 micro-
comprised of S6 and M2 to isol-
S6 or FLAG METER M2 is defec-
amperes.
ate the trouble.
tive.
k. Refer to figure 4-12 and make
k. If DEVIATION meter does not
k. DEVIATION meter
2-22.1
Change 1
