# SDR CALA2026080218186

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 31, 2026
- Submitted: August 3, 2026
- Operation: Air carrier
- Aircraft: [N63820](https://openairdocs.org/aircraft/N63820), registered now
- Make and model: Boeing 737924ER
- Aircraft serial: 43534
- Aircraft time: 39,273 hours, 14,440 cycles
- Engine: Cfmint CFM567B27
- System (JASC): [3400 · Navigation System](https://openairdocs.org/jasc/3400)
- Part: Charger
- Part number: 312BS1011
- Part serial: 4775
- Condition: Inoperative
- Location: Zone 100
- Part time: 33,542 hours, 12,415 cycles
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026080218186

## Discrepancy

ISFD WILL NOT TURN ON.  PERFORMED TROUBLESHOOTING IAW FIM 34-24-00-2, TASK 804, & WDM 34-24-15. FOUND NO OUTPUT VOLTAGE ON D4331J B12. REMOVED ISFD DEDICATED BATTERY CHARGER  IAW AMM 34-24-03-000-801 AND AMM 20-10-07-000-801.  INSTALLED SERVICEABLE ISFD DEDICATED BATTERY CHARGER.  TESTED GOOD IAW AMM 34-2 4-03-400-801.

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