Table 5-11. Troubleshooting - continued.

TM 9-1270-219-13&P

Table 5-11. Troubleshooting - continued.

Malfunction

Test or Inspection

Corrective

Action

Step 15 After 15 5 seconds the EPU SELF TEST lamp and the test set ADS FLR and ADS NO GO lamps should

extinguish. EPU BITE indicators are to be ignored.

I f the SELF TEST lamp, ADS FLR and ADS NO GO lamps all remain illuminated after 30 seconds, replace the

F r o n t Panel Assembly as specified in Section V. If the SELF TEST lamp only remains illuminated after 30

seconds, replace the Central Processor Unit as specified in Section V.

If the ADS FLR and ADS NO GO lamps only remain illuminated after 30 seconds go to Step 16. If all the lamps

extinguish correctly go to Step 20.

S t e p 16 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.

I f the EPU SELF TEST lamp does not illuminate or the BITE indicators on the EPU fail to show white replace

the Central Processor Unit as specified in Section V.

Step 17 Release SELF TEST on the EPU. The BITE indicators on the EPU should stay white. The SELF TEST lamp on

the EPU should remain illuminated.

I f the BITE indicators do not stay white or the SELF TEST lamp fails to stay illuminated replace the CPU as

specified in Section V.

Step 18 While observing the EPU BITE indicators press and release the EPU RESET switch. The BITE indicators on

the EPU should show black and the EPU SELF TEST lamp should remain illuminated.

I f any EPU BITE indicator stays white or the SELF TEST lamp fails to remain illuminated immediately after

release of the EPU RESET switch replace the Central Processor Unit as specified in Section V.

Step 19 After approximately 155 seconds the EPU SELF TEST lamp should extinguish.

E P U BITE indicators are to be ignored. If the EPU SELF TEST lamp remains illuminated replace the CPU as

specified in Section V.

Step 20 Set test set switch 8 to STAT 1 and observe the lamps of the DATA WORD display.

If lamps 1, 2, 3, or 4 of the DATA WORD display are illuminated replace the Central Processor Unit as specified

in Section V.

If lamps 5, 6, or 7 of the DATA WORD display are illuminated replace the Pressure Transducer Unit as specified

in Section V.

Step 21 Set test set switch S8 to STAT 2 and observe the lamps of the DATA WORD display.

If lamps 0, 1, 2, 3, 4 or 5 are illuminated replace the Analog Interface Unit as specified in Section V.

If lamp 6 is illuminated replace the Power Supply Unit as specified in Section V.

Step 22 Set S10 to PT- PS and measure the voltage at TP7 (+ve) and 8. The result should be 0V 100mV.

If the result is out of tolerance replace the Pressure Transducer Unit as specified in Section V.

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