# SDR ASAA2013073195711

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 31, 2013
- Submitted: August 6, 2013
- Operation: Air carrier
- Aircraft: [N570AS](https://openairdocs.org/aircraft/N570AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35185
- Aircraft time: 24,777 hours, 7,385 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Part number: 3989083
- Part serial: 9171
- Condition: Failed
- Location: Lt A/C Pack
- Part time: 24,047 hours, 7,527 cycles
- Stage of operation: TX
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2013073195711

## Discrepancy

LEFT PACK LIGHT COMES ON WITH RECALL.  EXTINGUISHES WITH RESET.  ACFT GROUNDED.  ACCOMPLISHED TASK 21-61-00-700-806-002 PACK/ ZONE TEMP CONTROLLER.  BITE TEST ON NR 1 CONTROLLER LOGGED MULTIPLE FAULTS ON MULTIPLE SYS.  SWAPPED NR 1 AND NR 2 CONTROLLERS.  FAULTS FOLLOWED CONTROLLER.  REPLACED NR 1 CONTROLLER AND REINSTALLED NR 2 CONTROLLER REF MM TASK 21-61-20.   NR 1 CONTROLLER NOW LOGS THIS PACK TCV FAULT.  ACCOMPLISHED FIM TASK 212-62, TASK 830, LT TEMP CONTROL VALVE - FAULT ISOLATION.  REPLACED NR 1 TCV (V139) REF MM TASK 21-51-10, GROUND VERIFICATION CHECKS NORMAL.

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