TM 55-4920-231-14
Table 5. Troubleshooting (Cont)
is present with no dc voltage
across the red and black coded
lugs, either the rectifier is
open or capacitor or motor is
shorted. Disconnect red lead from
the rectifier and recheck voltage
across red and black coded lugs of
rectifier. If dc voltage is now
present, capacitor or motor is
shorted) ,( See figure 10.)
Open lead between transformer
Repair or replace wiring harness
and rectifier. (Check voltage between
lugs 3 and 4 on transformer
and across yellow coded lugs of
rectifier. If voltages are not
identical there is an open lead
between them.) (See figure 10.)
Open transformer primary
Repair or replace wiring harness
winding or input leads. (Disconnect
plug mating with J1 and check
resistance between pins 1
Replace transformer.
and 2 at T1. Resistance check on
J1 between pins I and J.)
(See figure 10.) (Approx. 2.8
ohms.)
Open transformer, secondary
Replace transformer.
winding. (Check voltage
across terminals 3 and 4 of Tl,
25V (rms).)
IF zero voltage, disconnect a lead
Replace transformer.
from terminal 3 or 4 and recheck
voltage; if still zero trans-
former is defective.
(See figure 10.)
2
Indicator light does
Indicator lamp burned out.
Replace lamp (paragraph 84).
not illuminate but
the motor runs when
power switch is ON.
Repair or replace wiring harness
Open lead to indicator lamp.
(Check continuity.) (See figure
3
Fuse blows when
Repair or replace cable
Shorted lead in power cable.
power switch is
(Check for continuity and shorts.)
placed in ON position.
(see figure 10.)
Shorted leads to motor or pilot
Repair or replace wiring harness
light. (Check continuity and
for shorts.) (See figure 10.)
Replace filter (paragraph 60).
Short in suppression filter.
(Check continuity and for
shorts) (See figure 10.)
Replace motor (paragraph 81).
Short in electric motor (Check
continuity and for shorts). (See
Repair motor.
Shorted lead to switch or fuse.
Repair or replace wiring harness
(paragraph 85).
(Check continuity and for shorts.)
(See figure 10.)
AC OPERATION ONLY
Repair or replace wiring harness
Shorted leads to transformer or
shorted transformer primary
windings. (Check for con-
tinuity and for shorts.) (See
Replace transformer.
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