Table 5-11. Troubleshooting - continued.

TM 9-1270-219-13&P

Table 5-11. Troubleshooting - continued.

Malfunction

Test or Inspection

Corrective

Action

Step 6 Using the Digital Voltmeter, measure the voltage on test points 7 (+ve) and 8 with S10 set to 5V. The result

should be 5V 0.2V (Table 5-12).

If the voltage is out of tolerance replace Power Supply Unit as specified in Section V.

Step 7 Measure voltage on test points 7 (+ve) and 8 with S10 set to +15V. The result should be +15V + 0.5V.

If the result is out of tolerance replace the Power Supply Unit as specified in Section V.

Step 8 Measure the voltage on test points 7 (+ve) and 8 with S10 set to 15V. The result should be 15 0.5V.

If the result is out of tolerance replace the Power Supply Unit as specified in Section V.

Step 9 Measure voltage on test points 7 (+ve) and 8 with S10 set to LAI 15V. The voltage should be 15V + 1.0V.

If the result is out of tolerance replace the Power Supply Unit as specified in Section V.

Step 10 Measure voltage on test points 7 (+ve) and 8 with S10 set to LAI +15V. The voltage should be +15V 1.0V.

If the result is out of tolerance replace the Power Supply Unit as specified in Section V.

Step 11 Check the ADS FLR and ADS NO Go lamps on the Test Set.

If only one is on replace the Central Processor Unit as specified in Section V.

If both lamps are OFF go to Step 12

If both lamps are ON go to Step 16

Step 12 Press and hold SELF TEST on the EPU. The BITE indicators on the EPU should show white and the SELF

TEST lamp on the EPU should illuminate. The ADS FLR and ADS NO GO lamps on the test set should illuminate.

I f the EPU BITE indicators do not all show white or if the SELF TEST lamp does not illuminate, replace the

Front Panel Assembly as specified in Section V.

If the ADS FLR and ADS NO GO lamps on the test set do not illuminate replace the Central Processor Unit as

specified in Section V.

Step 13 Release SELF TEST on the EPU. The BITE indicators on the EPU should stay white and the SELF TEST lamp

should remain illuminated. The ADS FLR and ADS NO GO lamps on the test set should extinguish.

I f the EPU BITE indicators do not stay white, the SELF TEST lamp fails to stay illuminated or the ADS FLR

and ADS NO GO lamps on the test set fail to extinguish, replace the Central Processor Unit as specified

in Section V.

Step 14 While observing the EPU BITE indicators, press and release the EPU RESET Switch. The BITE indicators

o n the EPU should show black, the EPU SELF TEST lamp should remain illuminated and the ADS FLR and ADS NO

GO Iamps on the test set should be illuminated.

If any EPU BITE indicator stays white replace the Front Panel Assembly as specified in Section V.

If the EPU SELF TEST lamp or the ADS FLR and ADS NO GO lamps on the test set are not illuminated, replace

the Central Processor Unit, as specified in Section V.

5-23