TM 11-5821-284-34
Sequence
Doe
Trouble Symptom
Probable Cause
Corrective Action
No.
Test
If voltage is low, check AlCR21
and A1AR1 for short circuits.
d. Voltage at pin 8 of
Short or open in +5.1
If voltage is high, check A1CRP
circuit board A1 is
Vdc line.
for open circuit.
above or below +5.1
Vdc.
If voltage is low, check A1CR1,
A1A1 thru A1A6 and asso
ciated components for short
circuits. Check A1R1 for open
circuit.
8
5-11
Incorrect waveform at
Defect in sequential pulsing
a. If coupler runs and wave-
A1AR1-9 when limit switch
or servo amplifier circuit.
form is not correct check
S1 is tripped.
A1C9, A1L1, and A1Q19.
b. If a steady voltage between
+3.9 and +8.2 Vdc is observed
check AlQ18 gate voltage.
+28
(1) If AlQ18 gate is
Vdc check A11Q18 and
A1AR1. Check for short
circuit of A1C4. If
A1Q18 gate is 0 Vdc
check A1R1 and A1CR12
for open circuits and
R2 for short circuit.
(2) Check A1Q8 collector
voltage. If voltage is
above +3.0 Vdc, check
A1Q8 and A1C1 and
A1C2 for short circuits.
If voltage is below +0.3
Vdc check for bad A1Q10
c. If a steady voltage above
+8.2 Vdc is observed at
A1AR1-9, check A1Q14 col-
lector voltage.
(1) If A1Q14 collector is
below +0.3 Vdc proceed
to item 10e.
(2) If A1Q14 collector is
above + 0.3 Vdc check
A1Q14, A1CR9, A1R12
and A1R15.
d. If a steady voltage below
+ 3.9 Vdc is observed at
A1AR1-9 check A1Q12
collector voltage.
(1) If A1Q12 collector is
below +0.3 Vdc proceed
to item 10e.
(2) If A1Q12 collector is
above + 0 3 Vdc check
A1Q12, A1R19, A, Q1,
A1CR10, A1R13
and -A1R16
e. If voltage observed at A1Q14
or AlQ12 collector is below
+0.3 Vdc check voltage at
A1A4C-14.
(1) If A1A4C-14 is above
+3.0 Vdc proceed to item
10f.
4-3
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