AT3 Georgia Cowan and AT2 Justin Jarvis trouble shoot an automated testing equipment power cord.
When circuit cards of avionic components belonging to the airframes serviced by Fleet Readiness Center Southwest (FRCSW) need repair or troubleshooting, they often end up in the commands micro-miniature shop in Building 463. Manned by 11 FRCSW Sailors, the intermediate level work done in the shop plays a supporting role to the repairs made by the command to more than 30,000 components annually.
"Many of the circuit cards, or shop replaceable assemblies, are held in weapons replaceable assemblies, the containers that house avionic functions. We not only do micro-miniature work on circuit cards, but also cable and wire repairs," said Aviation Electronics Technician 3
rd Class Georgia Cowan. "We also do troubleshooting on the Huntron program which tells us what these components are supposed to be reading, or what their values are. The Huntron testing machine is typically used to detect and locate faulty components on circuit boards or cards. Sometimes we don't have a testing program so we take two identical cards, one of which is a known good. We'll compare it to the faulty card to isolate the component failure of that card," Cowan said. "If a component is burned it's an easy fix because it's a visual identification, but if it's internal, we have to use a multi-meter to locate it."
Other tools used in the shop include microscopes, soldering irons, soldering jets and the PRC 2000 which is a temperature controlling unit used for the removal and installation of surface mount and through-hole components.
"Different cards require different temperatures in the repair process. The highest we go is about 900 F," said AT2 Justin Jarvis. "We work on two basic types of circuit cards: The laminate, which is plastic and carbon-fiber based that takes roughly 600 degrees to solder anything to them, and the ceramic cards that range from 750-800 degrees. These are usually old and pretty thick, so we generally have to heat the boards too," he said.
Circuit cards that cannot be repaired are returned to the customer who may designate them as beyond capability of maintenance (BCM) and order new cards.
To qualify to operate the testers and perform circuit card repairs, Sailors must complete miniature and micro repair schools and must recertify the qualifications every 18 months. For cable repairs, training is offered at Marine Corps Air Station Miramar. "If you don't have the qualifications, you can't work on the circuit cards, but with cable repair its more of a hands-on training in the shop. They teach you how to use the encyclopedias of the connectors," Cowan said. "The shop repairs intercommunication systems (ICS) cables belonging to Naval Air Station North Island squadrons, and cross and power cables. ICS cables are attached to pilots helmets and cross cables are used on the bridge for ordnance," Jarvis noted.
The shop analyzes approximately 100 to 150 items weekly, and also operates an engraving machine to manufacture signs, plaques, and name tags for Naval Air Station North Island commands.