A customer states their computer was fine until yesterday when they heard a pop noise and the computer stopped working. Which of the following components should the technician test FIRST?

The main system board rarely produces a pop sound on failure and would not be the first component to suspect given the described audible symptom.

A processor failure typically does not produce an audible pop and usually results in gradual overheating or no-POST rather than a sudden noise and shutdown.

A hard disk drive can make clicking or grinding sounds during failure but does not typically produce a loud pop followed by a complete loss of power.

A loud pop noise originating from a desktop is most commonly caused by a capacitor failure or an internal short within the power supply unit, which would immediately cut power to the entire system. Because the PSU is the component most likely to produce such a sound and is the root cause for a sudden loss of power, it should be tested first before examining any downstream components.