# SDR UPS00431341

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 18, 2000
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N673UP](https://openairdocs.org/aircraft/N673UP), registered now
- Make and model: Boeing 747123F
- Aircraft serial: 20325
- System (JASC): [2620 · Extinguishing System](https://openairdocs.org/jasc/2620)
- Part: Light
- Condition: Inoperative
- Location: Cockpit
- Stage of operation: IN
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UPS00431341

## Discrepancy

LIGHTS INOP IN NR 4 FIRE HANDLE DURING FIRE TEST IN BOTH..  HOWEVER, LIGHTS WILL TEST INDEPENDENTLY IN EITHER A OR B.  T/S SYSTEM USING WDM 26-11-41 AND MM 26-11-00.  REPLACED K13 RELAY ON FIRE DETECTION MODULE.  SYSTEM OPS CHECKS OK PER MM 26-11-00.

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