Install guide

ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Table 4-11. CDU Testing and Troubleshooting — Continued
Malfunction
Test procedure
Normal indication
indication/corrective action
2b. Press EXECUTE switch-indica-
tor to on
2b-1. For solid state memory press
CDU keys SPH 800 ENT’
2c.
2d.
Compare printed checksum to
checksum written on either the
front of the diagnostic-alignment
tape or solid state program tape
Type TTY character set CDU
(selects CDU automatic test
model)
EXECUTE switch-indicator lights
TTY prints out:
(For core memory
only)
PADS DIAGNOSTIC
ALIGN-
MENT PROCRAM
PROGRAM CHECKSUM XXXXXX
SELECT TEST MODE
TTY prints out:
PADS SOLID STATE DIAGNOS-
TIC ALIGNMENT PROCRAM
PROCRAM CHECKSUM
SELECT TEST MODE
Checksums are equal
TTY prints out:
CDU
Xxxxxx
CDU AUTOMATIC TEST
MODE
CDU numeric displays 0 thru 9 at
2-second intervals.
Alha module
displays alternately
, +, and x
Checksum is incorrect
See step 3j of table 4-6 or step 3k of
table 4-6.1
From this step to completion of test,
a TTY CDU failure message listed
in table 4-13 may occur, Perform
corrective action specified in table
4-13
No CDU display
Replace cards in sequence given:
Keyboard and control circuit card
assembly A3
Display logic circuit card assembly
Al
Display logic circuit card assembly
A2
Before proceeding, check that TTY
has printed XXX CYCLES PASS.
2e. Press CDU LAMP button and
release within 2 seconds, Repeat
if necessary to observe indicators
CDU numeric module displays all
8’s
Alpha module displays . All dis-
play indicators are lighted
No change in display function:
Check wire harness continuity from
P1
Replace front panel assembly
All lamps do not light
Replace defective lamps
4-74
Change 5