Install guide
Section III. TESTING AND
4-8. General.
NOTE
The computer is the primary tester for
the CDU and IMU. Perform the com-
puter test to verify proper computer op-
eration before testing a CDU or IMU.
a.
General support troubleshooting of the PADS
consists of performing testing and troubleshooting of
the computer, CDU, PS, and computer power supply as
outlined on tables 4-6, or 4-6.1, 4-7, 4-11, 4-19, and
4-20, and IMU testing, alignment, and troubleshooting,
as outlined in table 4-14 or 4-14.1. Tables 4-6 and 4-14
use PADS test set punched tape reader, part no.
877406-1, and tables 4-6.1 and 4-14.1 use punched tape
reader, part no 877406-2. The equipment setup and
program load sequence described in table 4-6, 4-6.1,
4-6.2 and 4-6.3 is common for the computer, CDU, or
IMU. It should be noted that if an IMU dedicated
memory is used for the testing, the alignment data is
lost. Therefore, the IMU calibration tape must be
reloaded into the dedicated memory. If only computer
or CDU testing is to be performed, use a spare memory
instead of the IMU dedicated memory. If an IMU is
being tested, the IMU dedicated memory must be in-
stalled in the computer.
The procedures in the tables
are arranged in three columns. The first column con-
tains the test operation procedures to be performed.
The second column contains the normal indication to
be observed when the procedure has been performed.
The third column contains the corrective action to be
taken if the normal indication is not obtained. If a
corrective action is not given where a normal indication
is given, this normal indication is a function of the test
equipment, and if abnormal, the applicable technical
manual should be referred to for test equipment mal-
functions. Whenever a corrective action has been taken,
the complete testing and troubleshooting procedures
must be followed in the sequence given. All PADS
equipment must be installed in the primary pallet
during testing and troubleshooting.
b. There are two types of memory units available
for the computer; a core or a solid state memory. The
determination of the memory type is important because
the program loading instructions are different for each
memory. The memory type, if unknown, can be deter-
mined by following the steps in table 4-6 or 4-6.1.
c. The core memory contains only one program at
a time, either the diagnostic alignment program or the
operational program. Follow instructions in table 4-6 or
4-6.1 for diagnostic alignment program loading.
d. The solid state memory contains both the diag-
nostic alignment and operational programs. Loading of
ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
TROUBLESHOOTING
the solid state memory for diagnostic alignment and the
reloading for operation
is not necessary. Only IMU
calibration constants need be loaded when the memory
is to be dedicated to a different IMU. Refer to table
4-18, steps aa thru ba or table 4-18.1 steps ab through
bd for IMU calibration constants loading. In the event
that the solid state memory must be reloaded with the
solid state program, refer to table 4-6.2 or 4-6.3 for
loading instructions.
The tapes used in testing and operating
the PADS are electrically conductive.
DEATH OR SERIOUS INJURY, as well
as damage to tapes may result if the tapes
are allowed to come into contact with
115 VAC.
When removing, replacing or handling the
solid state memory, do not touch connector
pins or components on face of assembly as
damage to the memory may result.
Ensure that the solid state memory is
transported in conductive bag with CAU-
TION label identifying its contents as
static-sensitive device.
Prior to removal of the solid state mem-
ory from packaging, operator should dis-
charge static electricity by making arm
contact with earth ground.
4-9. Computer Testing and Troubleshooting Proce-
dure.
a. Test Equipment and Materials.
(1) PADS test set consists of the signal processor
unit (SPU) punched tape reader (tape reader), buffer
unit, interconnecting cables, and auxiliary equipment.
(2) Teletypewriter.
NOTE
The 100-wpm motor worm gear must be
installed prior to use. Refer to TM 11-
5815-200-12.
(3) PADS power supply, pallet frame, and battery
box.
(4) + 28V power source.
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