技術者が、ハイエンドのワークステーション PC の故障した PSU を交換しました。現在、PC は POST に失敗し、5 秒以上電源がオンのままになりません。インストール中に忘れられた可能性が高い電源接続は次のどれですか。
正解:B
The issue described suggests the 12V CPU power connector was likely forgotten during installation. The
12V power rail is essential for the operation of high-end workstation components, including the CPU.
Without the 12V connection, the system will fail to POST and may power off shortly after being turned on.
* Why 12V?
* The 12V connector is critical for providing power to the CPU via the motherboard. Modern CPUs require a dedicated power source from the PSU, usually supplied through the 4-pin or 8- pin EPS12V connector.
* If this connection is omitted, the motherboard will not receive adequate power for the CPU to function, resulting in the system failing to POST or shutting down after a brief period.
* Incorrect Options:
* A. 5V: The 5V rail powers USB devices, some motherboard components, and certain peripherals, but not the CPU directly.
* C. 120V and D. 220V: These voltages refer to the power supply's input from the wall outlet, not the internal connections to components.
CompTIA A+ Exam Objectives References:
* 220-1101 (Core 1), Section 3.5: Explains power supply requirements and troubleshooting scenarios related to component connections.