A user reports that their desktop PC does not turn on.

If a desktopfails to power on entirely, the most probable cause is afaulty Power Supply Unit (PSU). If there are no lights, fans, or POST beeps, the PSU may have failed, cutting off all power to the motherboard and components.

Option B (GPU):Could prevent video output, but the system would still power on and beep.

Option C (RAM):Missing or faulty RAM would cause POST errors but not prevent startup entirely.

Option D (CPU):A bad CPU may cause POST failure, but the system would usually at least power on.

CompTIA A+ Core 1 Exam Objective Reference:

Objective 3.5: Given a scenario, troubleshoot problems related to motherboards, RAM, CPU, and power.

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