The Marine Corps occupational field code 5900 is for electronic maintenance. Marines with this field code maintain, repair, and operate a variety of electronic equipment, mainly within the Marine Air Command and Control Systems (MACCS) network. They work on air defense and surveillance radar, aviation radio communications, air traffic control systems, and more. They must have a high level of technical competence and skills to maintain and operate this equipment.
The Basic Electronics Course (BEC) teaches entry-level Marines basic electricity, electronics, digital logic, computer operation, circuit principles, troubleshooting, and soldering. This course prepares them to attend follow-on electronic equipment repair courses specific to their MOS.