Set the voltage on the power supply to 110V or 115V. The power supply must be. After you have finished installing the power supply into your computer case, the next step in the PC building process is to wire the PSU to the correct locations within your new system. In this beginner friendly walkthrough we will go over everything you need to know about this process, including. A connector for connecting to the motherboard to power the CPU, its integrated graphics, memory controllers, and overall the VRM of the motherboard, which is different from the main 24-pin power connector. It provides the necessary power for all components, including the CPU, GPU, and drives, to function properly. Keep in mind that if your computer came pre-assembled, you don't need to install the power.