# SDR ASAA2021100536210

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 5, 2021
- Submitted: October 8, 2021
- Operation: Air carrier
- Aircraft: [N533AS](https://openairdocs.org/aircraft/N533AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35201
- Aircraft time: 39,634 hours, 11,476 cycles
- System (JASC): [2160 · Cabin Temperature Control System](https://openairdocs.org/jasc/2160)
- Part: Modulating Valve
- Part number: 3989085
- Part serial: 2088
- Condition: Faulty
- Location: Left Ecs Bay
- Part time: 91,683 hours, 42,225 cycles
- Stage of operation: TX
- 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/ASAA2021100536210

## Discrepancy

DURING AFTER START CHECKLIST LEFT PACK LIGHT CAME ON. LIGHT WENT OUT WHEN MASTER CAUTION RESET. GROUNDED - YES. REMOVED AND REPLACED LH PACK TCV AS REQUIRED REF B737-800 AMM 21-51-10-000-801 LEAK CKD GOOD NO LEAKS NOTED. PERFORMED BITE CK NO FAULTS FOUND REF AMM 21-61-00-700-806-002.

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