Field-Replaceable Units (FRUs) Which of the following is NOT typically classified as a field replaceable unit in standard PC service practice?

Introduction / Context:
FRUs are parts intended to be swapped quickly in the field without board-level repair. Identifying what is and is not a FRU streamlines spare parts inventory and service procedures.

Given Data / Assumptions:

• Typical FRUs include plug-in cards, power supplies, memory modules, storage devices, and some socketed ROMs.
• Structural elements (cases/chassis) are not commonly stocked as FRUs for rapid replacement, except in depot or warranty rebuild scenarios.
• We refer to common PC service contexts.

Concept / Approach:

System ROM chips (or modules) and video controllers are replaceable components; power supplies are classic FRUs. By contrast, the system chassis is a mechanical enclosure; while it can be replaced, it is not typically a quick-swap FRU in field service due to labor, wiring, and regulatory labeling considerations.

Step-by-Step Solution:

Verification / Alternative check:

Service manuals and parts catalogs classify PSUs, cards, and modules as FRUs; chassis typically falls under mechanical assemblies replaced in depot service rather than quick field swaps.

Why Other Options Are Wrong:

System ROM, power supply, and video controller are all routinely replaced in the field. “None of the above” is therefore incorrect.

Common Pitfalls:

Assuming that because an item can be replaced, it is automatically a FRU. FRU implies standard stocking and streamlined replacement procedures.

Final Answer:

System chasis