C8, TM 9-2350-230-12
TABLE 8-4. TROUBLESHOOTING - CONTINUED
Malfunction
Probable cause
Corrective action
MISSILE SUBSYSTEM -
Continued
120. 13. 1.
Gunner's ready
Check switch for proper opera-
lamp glows
adjustment or defective
tion. Adjust or replace.
with trans-
mitter door
closed.
120. 14. Null meter
a.
Rate sensor defective
a.
Replace rate sensor if:
needle does not
deflect when
(1) Audible hum is not heard
turret is moved
from rate sensor and
in azimuth or
elevation
(2) Rate sensor is not warm
to touch.
b.
Test checkout panel
b. Replace test checkout panel.
defective
Repeat test.
c. Defective gyro selector
c. Replace gyro selector.
d. Replace board 4A6.
121.
(System self-test
a. All firing conditions not
verification)
present
that "conditions prior to
Tracker motor
firing" are present.
does not run when
fire trigger is pulled
b.
No fire pulse to test checkout
b.
Disconnect cable from test
panel
checkout panel 7J2 and
monitor on the cable plug
between pins "C" (POS)
"G" (GROUND) for the
fire pulse, as fire trigger
is pulled. If fire pulse is
not present, check for
loose cable connectors at
relay box, loader's control
box, gun launcher, acces-
sory box.
c.
Test checkout panel
c. If fire pulse is present at
defective
(7J2) test checkout panel
and tracker does not run,
replace test checkout panel,
Repeat test. If problem
is not corrected, request
supporting maintenance.
8-38.8