# SDR E81R201112222202

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 22, 2011
- Submitted: December 28, 2011
- Operation: Air carrier
- Filed by: [Chronos Aviation, LLC., repair station E81R759X](https://openairdocs.org/faa-repair-station/E81R759X/chronos-aviation-llc.md) (OpenAirDocs)
- Aircraft: [N832QS](https://openairdocs.org/aircraft/N832QS), registered now
- Make and model: Raythn HAWKER800XP
- Aircraft serial: 258683
- Aircraft time: 4,349 hours, 3,131 cycles
- System (JASC): [3150 · Central Warning](https://openairdocs.org/jasc/3150)
- Part: Circuit Board
- Part number: 256NF190943A
- Condition: Damaged
- Stage of operation: IN
- How discovered: 9
- Nature of condition: N
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/E81R201112222202

## Discrepancy

INVESTIGATED PILOT REPORT OF BOTH MWS ANNUNCIATORS NOT ILLUMINATING AND FLASHING DURING PRE-FLIGHT TESTS OF ENG NR 1 AND ENGINE NR 2 ENGINE FIRE WARNING SYS TESTS.  ALSO NOTED BOTH MWS ANNUNCIATORS WOULD NOT FLASH WHEN ANNUNCIATOR OVERIDE SWITCH MOVED FROM DIM OVERIDE TO NORMAL POSITION. CONFIRMED FAULT INDICATIONS.  VERIFIED DA/L PANEL CIRCUIT BOARDS "G" AND "AF" INPUTS AND CONNECTOR CONDITIONS OK.  IAW TECH SUPPORT, THE PN 25-6NF1909-43A CIRCUIT CARD "G" HAS DESIGN FAULT THAT CAN CAUSE REPORTED INDICATED CONDITION. REPLACED THE DA/L PANEL "G" CIRCUIT BOARD ASSY WITH NEW PN 25-6NF1909-63A CIRCUIT BOARD.  MWS AND ENGINE FIRE TEST ANNUNCIATOR INDICATIONS NORMAL. RECOMMEND AIRFRAME MFR OFFER THE IMPROVED PN 25-6NF1909-63A CIRCUIT BOARD UNDER A RECOMMENDED SB OR MODIFICATION.

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