System Build and Termination

System Build and Termination

This lab brings together every major skill you have developed throughout the program. You will construct a complete integrated electronics and telecom system in a single extended session, moving through three distinct work stations: PCB soldering, copper structured cabling, and fiber optic termination. At each station a hold-point inspection locks in quality before you move forward. Workmanship standards are not suggestions—they are the same criteria employers and credential exams use to evaluate your work.

Safety First: LOTO and PPE for Every Station

Before you touch any equipment, review the hazard controls for each station.

Soldering station: Flux fumes are an inhalation hazard. Position the fume extractor nozzle within two inches of the work surface and verify it is running before you apply heat. Wear safety glasses at all times—solder can spatter. Use an ESD wrist strap bonded to a common ground point to protect static-sensitive components. The soldering iron tip exceeds 600 °F; set it down only on the iron holder and never rest it on the bench. If you are working on a live bench power supply that feeds the board under test, apply lockout/tagout (LOTO) to isolate the supply before probing or reworking joints. One lock, one tag, verify zero energy before you touch.

Copper cabling station: Punch-down tools generate spring-loaded force; keep fingers clear of the blade side. Safety glasses prevent insulation fragments from entering your eyes. When mounting rack hardware, use two people to hold heavy sections—rack rails and patch panels can pinch fingers. Confirm all rack-mounted equipment is de-energized and LOTO is applied before drilling or cable-stapling near existing infrastructure.

Fiber optic station: Cleaved and polished fiber end faces produce invisible glass shards. Collect all fiber scraps in a puncture-resistant sharps container—never on the bench or floor. Do not look directly into a fiber connector unless you have confirmed with a power meter or visual fault locator that no optical source is active. Wear safety glasses. Use IPA (isopropyl alcohol) and lint-free wipes in a well-ventilated area; IPA is flammable, so keep it away from the soldering station.

Station 1 — Soldering the PCB Subassembly

Start with through-hole components (resistors, capacitors, connectors) because their leads give you physical feedback during insertion. Seat each component flush to the board, bend leads slightly to hold position, then solder. A good solder joint is smooth, shiny (when using leaded alloy), concave-fillet shaped, and wets both the pad and the lead. An insufficient joint appears dull, grainy, or balled—this is a cold joint and must be reflowed.

For surface-mount devices (SMDs), apply a thin bead of solder paste to each pad using the stencil or a syringe, place components with tweezers, and reflow with the SMD rework station. Hold the hot-air nozzle at the manufacturer-recommended height and temperature—too close or too hot will lift pads or tombstone small passives.

Inspect every joint against IPC J-STD-001 criteria before calling for your hold-point check. Critical defects (shorts, opens, lifted pads that break the circuit) must be zero. Minor defects (excess solder, slight misalignment that does not affect function) must be fewer than three across the board.

Station 2 — Copper Structured Cabling

Your four-drop Cat 6 run will serve as the distribution backbone of your integrated system. Follow TIA-568 wiring standards throughout. Cat 6 requires that the pair twist be maintained as close as possible to the termination point—untwist no more than the connector manufacturer specifies, typically one-half inch or less. Use the T568B pinout (or T568A consistently) across all patch panel ports and keystone jacks; mixing pinouts creates a miswired link.

Punch down keystone jacks with the 110-style punch-down tool: seat the wire firmly in the slot, position the tool with the cut side toward the wire tail, and strike once with firm pressure. Route cables in horizontal bundles, maintain consistent bend radius (no kink tighter than four times the cable diameter for Cat 6), and dress with hook-and-loop fasteners—never overtighten cable ties, which can deform the jacket and degrade performance.

Mount the patch panel and two-post rack section following BICSI installation practices: verify the rack is plumb and level before fastening, torque cage nuts to spec, and leave one rack unit of space above and below active equipment for airflow. Label every port and cable run with the label maker using a logical scheme recorded in your as-built documentation.

Station 3 — Fiber Optic Termination

You will terminate three SC and three LC connectors using two methods: pre-polished/splice-on (mechanical splice inside the connector body accepts a cleaved fiber stub) and epoxy-and-polish (adhesive bonds the fiber in the ferrule, then you polish through decreasing grits on a polishing puck).

For epoxy-and-polish: inject adhesive into the connector, insert the stripped and cleaved fiber until it protrudes slightly from the ferrule, cure per the adhesive instructions, scribe-and-break the excess fiber flush, then polish through the grit sequence on the polishing film. For pre-polished: strip and cleave the fiber to the specified length, insert it into the connector until you feel the internal splice engage, and lock the connector body.

Clean every end face with a one-stroke fiber optic cleaning tool or IPA-dampened lint-free wipe before inspection. Inspect with the fiber optic inspection scope at 200–400× magnification. Accept faces that are smooth, free of scratches through the core, and free of contamination. Reject and re-clean or re-terminate any face showing core damage, pits, or debris. Only mate clean, inspected connectors.

Hold-Point Sign-Off

At each of the three hold points, call the instructor before proceeding. Bring your workmanship checklist, your labeling documentation, and the cleaned, inspected connectors. The instructor will verify zero critical defects and fewer than three minor defects at each station. Passing all three hold points completes the build phase of your capstone project.