SEGMENT 1

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. 7-23