If you are willing to learn more about motherboard quality you must deeply study the voltage regulator circuit, which is in charge of taking the voltage provided by the power supply – namely +12 V – and converting it into the appropriate voltage required by the CPU, memories, chipset and other circuits present. In this tutorial we will present an in-depth trip inside the motherboard voltage regulator circuit, showing you how to identify this circuit, how it works, what the most common projects are and how to identify good-quality components.

The quality of the voltage regulator circuit is one of the best ways to have an idea about the overall motherboard quality and life-span for several reasons. A good voltage regulator won’t have any fluctuations or noise on its outputs, providing the CPU and other components with a clean and stable voltage, making them to work perfectly. A bad voltage regulator can lead to fluctuations or noise on the voltage that will lead to malfunctions like the computer crashing, resetting and presenting the infamous Blue Screen of Death on Windows.

If this circuit uses low-quality electrolytic capacitors they will leak, swell or even explode. Frequently when a motherboard dies it is this circuit that goes bad. So having a good-quality voltage regulator circuit will ensure that you will have a stable system that will last for years.

Recognizing this circuit is pretty easy. Since it is the only circuit on the motherboard that uses chokes (a kind of coil), locate the chokes and will have located the voltage regulator circuit. Usually this circuit is around the CPU socket, but you will find some chokes spread on the motherboard, usually near the memory sockets and near the south bridge chip, as they will be providing the right voltage to these components.

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Figure 1: Voltage regulator circuit.

Before explaining exactly how this circuit works, first let’s make you acquainted with the main components found on the voltage regulator circuit.