TM 11-5821-284-34
Sequence
Doe
Trouble Symptom
Probable Cause
Corrective Action
No.
Test
f. (1) Incorrect voltage
Defect in WAND gates.
If output voltage does not go
at pin 13, 14 or 15
high when input to low voltage
of circuit board
circuit is grounded in TEST
A1 when one gate is
CHART step 6a and b, check
grounded.
circuits related to NAND gate
(A1A3A, A1ASB, or A1ASC)
being checked
(2) Incorrect voltage at pin
Defect in NAND gates.
If output voltage does not go
13, 14, or 15 of
low when input to high voltage
circuit board A1
circuit is grounded in TEST
when remaining
CHART step &c and d, check
gate is grounded.
circuits related to NAND gate
(AlA3A, A1A3B, or A1A3C)
being checked.
g. Incorrect voltage at
Defect in sequencing circuit.
Check A1R20, A1R21, and AlQ.13.
collector of A1Q13
when RF power is
h. Incorrect voltage at
Defect in NAND gates or
Check inputs A1A4A-1, 2, and 3.
AIA4A6.
servo rotation logic
If all are high check A1A4.
Note. A1A4A-5 should be
below +0.3 Vdc only when
A4A-1 is high and A4B-8 is
low.
i. Incorrect voltage at
Defect in NAND gates or
Check inputs A1A4B-6, 7, and 8.
A1A4B-9.
servo rotation logic.
If any are low check A1A4.
Note. Voltages should be high
only when A4B-8 is low.
j. Incorrect voltage at
Defect in NAND gates.
Check AlA5.
A1A5A-8.
k. Incorrect voltage at
Defect in WAND gates.
Check A1A5.
A1A5B-7.
l. (1) Incorrect waveforms
Defect in NAND gates or
If any waveforms are missing,
at A1A3A3,
flip-flops.
check AlA3. If waveforms are
A1A3B-7, or
not properly sequenced, check
AlA3C-l.
A1A1 and A-1-2.
(2) Incorrect waveforms
Defect in flip-flops.
Check AQA1 and AlA2.
at A1ASA-3,
A1A8B-7, or
AA1 C-11 when
limit switch 52 is
tripped.
m. Incorrect waveforms at
Defective sequencing logic
Check AQI, AlQ2, AlQ3, s
pins 13, 14, and 15 of
circuits.
AlQ4, A~1Q5, A1Q6 and
circuit board A1.
assisted circuits. If no output
check AICRI.
10
5-13
Note. This procedure is
performed on antenna
model 437SAA only.
a. Incorrect voltage at
Defect in AlA6.Check AlA6.
A1A6B-7.
b. Incorrect voltage at
Defect in AlA6.Check AlA6.
A1A6C-11
c. Incorrect voltage at AlQl6
Defect in A1Q16.
Check AldQl6 and A1RA1.
collector.
d. Incorrect voltage at
Defect in A1AS
Check AlA6.
A1A6A43.
e. Incorrect voltage at
Defect in AlQI5.
Check AIQ1S and A1R, 7.
A.QIS collector.
4-5
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