TM 5-6350-275-24&P
Table 3-6. J-SIIDS Interface Assemblies, DS Maintenance Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. J-SIIDS STARGATE FAILURE (FO-7)
Step 1. On the Stargate PWA, monitor U22 LED 1 (+5 v power). The LED should be on.
If LED is not on, check for 20 VAC on TBI, pins 1 and 2.
If voltage is not present, replace J-SIIDS power supply.
If voltage is present and the LED is not on, replace the Stargate PWA (Stargate 1000, Para. 3-89).
If the LED is on, go to Step 2.
Step 2. Monitor the RTS, TD, CD, and RD LEDs on the MOD2-II modem PWA. The LEDs should be flashing on
and off.
If the LEDs are flashing on and off, communication from the PMC CPU to the MOD2-II modem PWA is good.
Go to Step 3.
If the LEDs are not flashing on and off, adjust R18 (TX) level and R10 (RX) level, adjust until the LEDs begin
flashing on and off.
If the LEDs are still not flashing on and off, check for +12 v across J1 pins 1 and 2 on the modem PWA.
If voltage is present, replace the modem PWA (Para. 3-90).
If the LEDs are still not flashing on and off, go to Table 3-1 and troubleshoot Malfunction 3.
If Malfunction 3 tests good, down load RSE to stargate and recheck. (Para. 3-132)
If the +12 v is not present at the Mod 2-11 modem J1 pins 1 and 2, go to Step 4.
Step 3. On the Stargate PWA, monitor the Comms channel Tx LED 2 and the Comms channel Rx LED 3 on U22.
The LEDs should be flashing on and off if communications between the RADC and the PMC CPU has been
established. Also LEDs 5 and 6 (STN AD and GD PKT) on U23 should be flashing on and off.
If the LEDs are flashing on and off, the communications channel within the RADC is good. Have comms lines
from the PMC CPU to RADC checked for excess noise. (checked by telephone company)
If the LEDs are not flashing on and off, go to Step 4.
Step 4. On the Stargate PWA, check for +12 v across TB1 pins 3 and 4.
If voltage is present, repair the wiring between TB1 pin 3 and 4 and MOD2-II modem connector J1 pins 1 and 2.
If voltage is not present, replace the Stargate PWA (Stargate 1000, Para. 3-89).
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