ARMY TM 5-6675-238-14
MARINE CORPS TM 08839A-14/1
Table 8-6. PADS Test Set Self- Test Procedure - Continued
Malfunction indication
Test procedure
Normal indication
corrective action
aa.
ab.
Turn TTY keyboard MOTOR
switch to OFF
Press SELF TEST switch-indi- SELF TEST switch-indicator goes
cater to off
off. EXECUTE switch-indicator
lights. FAILUR/ACTION in-
dicator displays 77
a. If the receive circuit bias current is
correct or can be adjusted, perform
the send circuit test, Remove cable
W212 P1 from SPU and set meter u
)
to read DC volts. Place positive (+
lead of meter on pin 2 of J12 (TTY
connector on front of SPU) and nega-
tive (-) lead of meter on pin 1 of J12.
Meter should indicate + 30V. If me-
ter does not indicate + 30V, replace
Al. If meter does indicate + 30V, set
up meter to read current. Place posi-
tive (+) lead of meter on pin 2 of J12
(TTY connector on front of SPU) and
negative (-) lead of meter on pin 1 of
J12. Meter should indicate 39 mA
±3mA. If meter does not indicate 39
mA, replace A1. If meter does indi-
cate 39 mA, proceed to next step
b. Adjust the rangefinder mechanism lo-
cated on the left side of the TTY by
typing RY and observing the printout.
Adjust the rangefinder clockwise until
the TTY prints other than RY. Note
the position of the rangefinder dial.
Now turn rangefinder counterclock-
wise and observe correct RY printout
and continue in a counterclockwise
direction until other than RY is
printed out. Note this position of the
rangefinder dial. Set the rangefinder
in the middle of the two extremes
c. If TTY still does not print out cor-
rectly, replace or repair TTY
SELF TEST switch-indicator does not
go off:
a. Check SELF TEST switch-indicator
for proper operation or shorted
wiring
b. Replace A3
EXECUTE switch-indicator does not
light: Replace buffer unit, then A1,
and then A3
8-53
