# SDR ASAA2013071095542

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 10, 2013
- Submitted: July 12, 2013
- Operation: Air carrier
- Aircraft: [N592AS](https://openairdocs.org/aircraft/N592AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35190
- Aircraft time: 21,015 hours, 6,597 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Control Valve
- Part number: 3989083
- Part serial: 11808
- Condition: Failed
- Location: A/C Pack
- Part time: 14,470 hours, 4,504 cycles
- Stage of operation: NR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2013071095542

## Discrepancy

COULD NOT COOL AFT CABIN - NO LIGHTS ILLUMINATED.  AFT SUPPLY DUCT STAYS AT 28 DEGREES C, AFT CABIN TEMP ( PASS CAB) INDICATES 32 DEGREES C.  MX CONTROL TROUBLESHOOT INFLIGHT WAS UNSUCCESSFUL.  ACFT GROUNDED.  CONFIRMED PROBLEM.  RAN VERIFY TEST ON NR 1 ZONE TEMP CONTROLLER - FAULTS AFT PAX CABIN TRIM VALVE.  REPLACED NR 1 ZONE TEMP CONTROL VALVE REF MM 21-61-21.  AFT CABIN TRIM VALVE, OPS NORMAL, REF MM 21-61-21.  ETOPS GROUND VERIFICATION TEST SUCCESSFUL.

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