After installing a second processor and corresponding heatsink into a server, an administrator notices that the new processor is not showing up during POST. Which of the following could be the cause…

An insufficient power supply would typically prevent the server from powering on at all or cause system-wide instability, not the selective absence of a single processor during POST.

Each processor socket on a multi-socket server motherboard requires a dedicated VRM to step down and regulate the voltage supplied to that CPU. Without the VRM seated in place, the processor lacks properly regulated power and cannot complete initialization, so the system firmware skips it entirely during the Power-On Self-Test hardware enumeration.

IRQ settings govern interrupt request lines used for hardware communication after the OS boots, and play no role in whether a processor is detected during POST.

DMA settings control how peripheral devices transfer data to memory and are completely unrelated to processor detection during the Power-On Self-Test.