# SDR CA120824003

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 22, 2012
- Submitted: September 14, 2015
- Operation: General aviation
- Make and model: Bell 412
- Registry model: [Bell 412](https://openairdocs.org/model/bell-412) (OpenAirDocs)
- Engine: Pwa PT6T3
- System (JASC): [3310 · Flight Compartment Lighting](https://openairdocs.org/jasc/3310)
- Part: Transistor
- Part number: 1300071
- Condition: Failed
- Location: Instrument Light
- Stage of operation: NR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA120824003

## Discrepancy

(CAN) WHEN THE DIM FUNCTION ON THE CONSOLE IS UTILIZED FOR THE INSTRUMENT LIGHTING, THE CIRCUIT BREAKER TRIPS. TRANSISTOR, PN 130-007-1 USED IN THE SYS HAS FOUND A GROUND ON THE BASE OR CASE.  THE INSULATOR SEPARATING TRANSISTOR FROM ALUMINUM BRACKET IS A PLASTIC WASHER AND A STRIP OF TAPE THAT OVER TIME DETERIORATES DUE TO VIBRATION AND EXPOSURE WHICH RESULTS IN A POPPING CIRCUIT BREAKER.

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