May be required to do some: lay out, build, test, troubleshoot, repair, and modify developmental and production electronic components, parts, equipment, and systems, such as computer equipment, test equipment, and machine tool numerical controls, applying principles and theories of electronics, electrical circuitry, engineering mathematics, electronic and electrical testing, and physics. Installations include building and testing wiring harnesses based on design documents, troubleshooting, repairing, and modifying electrical wiring where necessary and applying principles and theories of electronics, electrical circuitry, and electronic and electrical testing.