TM 11-6625-820-45
b. Connect P2 and P3 of the test set to the
Multimeter connection
Proper indication
(ohms)
aid box.
To
From
c. Connect the test set to a 27.5 volt dc pow-
W of J2
A of J2
e r source, a n d a 115-volt, 400-cps power
g of J2
A of J2
source.
V of J2
A of J2
d. Set the power switch on the control unit
h of J2
A of J2
to PWR.
U of J2
A of J2
i of J2
e. Connect the dc lead of the multimeter
A of J2
T of J2
A of J2
to the junction of Zener diode CR1 and re-
j of J2
A of J2
sistor R8. Connect the COMMON lead to the
S of J2
A of J2
anode of Zener diode CR1.
X of J2
A of J2
X of J2
R of J2
0.05. If the indication is improper, replace
X of J2
K of J2
E of J1
G of J1
the defective Zener diode CR1.
g. All other circuits in the aid box may be
checked by using the resistance chart in para-
t h e aid box before attempting resistance
measurements. When an improper resistance
2-7. Troubleshooting Control Unit, RMI
reading is obtained, refer to the schematic di-
OBS Indicator, and Test Set
agram in figure 15 to isolate the trouble.
a. Perform the general support testing pro-
2-6. Resistance Chart for Aid Box
cedures for the aid box in paragraph 47. If
the general support testing procedures indicate
Multimeter connection
trouble, perform the troubleshooting proce-
Proper indication
dures described in paragraph 2-5.
To
From
(ohms)
b. Connect the test set to the aid box and
22,900 2,290
a of J2
A of J2
external power as shown in figure 2-1.
0
J of J2
X of J2
n of J2
0
J of J2
c. Set the power switch on the test set con-
Y of J2
0
J of J2
trol unit to OFF.
b of J2
0
J of J2
d. Set the VOR/LOC-GLIDE SLOPE switch
C of J2
1,000 100
J of J2
on the test set to VOR/LOC. (All other switch-
511 51
B of J2
J of J2
P of J2
1,000 100
J of J2
es and controls may be set in any position. )
N of J2
0
J of J2
e. Perform the procedures in the trouble-
E of J2
0
J of J2
shooting chart in paragraph 2-8. This chart
36,500 3,650
m of J2
A of J2
gives various operational procedures for the
42,500 4,250
Z of J2
A of J2
test set. The proper indication for each op-
1,500 160
G of J1
L of J2
H of J1
D of J1
0
erational procedure is then given. If the equip-
0
K of J1
C of J1
ment produces an improper indication, the
160 20
t of J2
A of J2
chart lists the probable trouble and, in the
160 20
k of J2
A of J2
Correction column, suggests how to isolate the
160 20
p of J2
A of J2
160 20
trouble.
f of J2
A of J2
C h a n g e 2 2-3
