TM 11-6625-3081-23
7-4. DC POWER SUPPLY ASSEMBLY 1A4
7 -4
INPUT CODE:
FPSST (cont)
c. SEGMENT 1
1. VDT DISPLAY
+28 VOLT POWER SUPPLY FAILED ACCEPTABLE LIMITS.
REPLACEMENT PROCEDURES.)
REF. DES.
PART NO.
REPLACE ACTION IN THE ORDER LISTED. (REFERENCE
NAME
PERFORM THE FOLLOWING
TM 11-6625-3081-23 FOR
1. 1A4PS1
BFK28-4
2. 2A2A13XX
AC4720
3. 2A2A7A6A4
13082738
+28 VDC SUPPLY
DIFF. INPUT CCA (J8)
TEMP. MONITOR CCA
NOTE:
ATTEMPT ADJUSTMENT OF THE SUPPLY PRIOR TO REPLACEMENT.
2. CORRECTIVE ACTION - SEGMENT 1
NOTE
Corrective actions for FPSST fault segments are
identical except for power supplies. Refer to the VDT
display for each fault segment for the correct power
supply to be replaced.
(a) Remove applicable power supply:
1A4PS1
+28 vdc
Power Supply
1A4PS2
+15 vdc
Power Supply
1A4PS3
-15 vdc
Power Supply
1A4PS4
+5 vdc
Power Supply
Check contacts of mating connectors and repair if required. Install
replacement power supply and perform FPSST test.
If FPSST test passes,
no further action required.
If this segment displayed again, proceed
to (b).
If another segment displayed, proceed to that segment and
continue troubleshooting.
(b) Remove Differential Input CCA 2A2A13XX. Check contacts of mating
connectors and repair if required.
Install replacement 2A2A13XX and
perform FPSST test.
If FPSST test passes, no further action required.
If this segment displayed again, proceed to (c). If another segment
displayed, proceed to that segment and continue troubleshooting.
(c) Remove Temperature Monitor CCA 2A2A7A6A4. Check contacts of mating
connectors and repair if required.
Install replacement 2A2A7A6A4 and
perform FPSST test.
If FPSST test passes, no further action required.
If this segment displayed again, proceed to (d). If another segment
displayed, proceed to that segment and continue troubleshooting.
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