ユーザーがコンピュータの電源を入れると、ファンは起動しますが、マシンは POST しません。この問題のトラブルシューティングを行うために技術者が最初に実行すべき手順は次のうちどれですか。
正解:A
Testing the power supply first ensures that the correct voltage is reaching all components, which is a common cause of boot issues. Modifying BIOS settings is not possible without a POST. Checking PCIe cards or replacing the motherboard are secondary steps if the power supply is functional. CompTIA A+ Core 1 objectives cover power supply testing as an essential troubleshooting step in system startup issues.