Install guide
ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Table 3-3. Direct Support Troubleshooting
Malfunction
Probable cause Troubleshooting/corrective action
NOTE
Fault indicators are normally black. Before applying power, inspect CDU, computer, and
PS for set (white) fault indicators and record for troubleshooting. Change fault indicators
from white to black by pressing LAMP after power has been applied.
If a malfunction occurs, recycle power and restart the test to verify. If more than one
fault indicator is set, the most likely defective unit (in priority order) is PS, computer,
CDU, and IMU. Cables are also suspect.
Because a computer memory module contains calibration data for a specific IMU, the
memory module and IMU must be replaced as a matched set. To check the serial number
of the IMU a particular memory is programmed for, press MON, ID,1,8, ENT.
The dis-
day should read 18 M, XXX, where XXX represents the IMU serial number. The Julian
date of the calibration data is in MON ID location 17.
1. BATTERY circuit breaker CB1
and/or VEHICLE circuit
breaker CB2 do not stay ON
2. When the ON/OFF button is
pressed to turn system on, the
system shuts down when the
button is released or PADS does
not turn on when ON/OFF
button is pressed, but BATTERY
and VEHICLE circuit breakers
CB1 and CB2 stay ON and no
malfunction flags are set
3. PADS stays on momentarily
after release of ON/OFF
button or shuts down with no
fault indicator set
a.
b.
a.
b.
c.
d.
e.
a.
b.
Defective circuit breaker
Short in PS
Power source not on or
improper test set up
Defective PS
Defective cable W 1 or W3
Defective CDU
Defective computer
PADS overheated
Defective IMU overtemp
thermostat
c.
Defective PS
Replace PS. Refer to para 3-13d
Replace PS. Refer to para 3-13d
Check electrical connections as shown in
figure 3-1
Replace PS. Refer to para 3-13d
Check cables. Refer to para 3-7. Replace as
necessary
Replace CDU. Refer to para 3-13a
Replace computer. Refer to para 3-13b
a. Let system cool down
b. Check fan operation. Refer to steps 4,
5, and 6
c. Clean cooling system. Refer to
TM 5-6675-308-12 and/or
TM 08837A-12/l
a. Turn PADS off and disconnect W5P2
from PS connector 3J1
b. Measure resistance between pins G and H
of W5P2
c.
If resistance is less than 100 kilohm,
replace IMU. Refer to para 3-13c
d. Reconnect W5
Replace PS. Refer to para 3-13d
3-12
Change 6