# SDR ASAA2021122537007

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 25, 2021
- Submitted: December 29, 2021
- Operation: Air carrier
- Aircraft: [N577AS](https://openairdocs.org/aircraft/N577AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35186
- Aircraft time: 52,877 hours, 15,710 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Unknown
- Part number: UNKNOWN
- Condition: Unknown
- Location: Unknown
- Stage of operation: NR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2021122537007

## Discrepancy

CONTROL CABIN ZONE TEMP LIGHT ILLUMINATES W/ MASTER CAUTION, AND RESETS W/ MASTER CAUTION. GROUNDED - YES. PER B737-800 FIM 21-62 TASK 842, #2 ZONE TEMP CONTROLLER SHOWS FAULT OF FLIGHT DECK PRIMARY TRIM VALVE. FURTHER T/S PER FIM 21-62 TASK 842 BITE TEST OF PZTC 1 AND 2 REF B737-800 AMM 21-61-00-700-806-002. NO FAULTS NOTED AND BOTH PZTC 1 AND 2 SHOW GREEN GO LIGHT. RAN APU PACKS FOR 5 MIN AND NO FLIGHT DECK FAULTS NOTED.

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