A power supply unit is the primary energy conversion module for an electronic device. It steps down dangerous mains voltage, rectifies it to DC, and uses switching regulators or linear regulators to provide stable, filtered rails to the internal components.
The system keeps resetting under heavy load, so hook a scope to the 5V rail and see if the PSU is sagging.
Never open a high-wattage PSU unless you know how to safely discharge the primary filter capacitors, which can hold a lethal charge long after being unplugged.
Also heard as
- power supply
Related terms
SMPS
A switched-mode power supply uses high-frequency switching to efficiently convert electrical power.
Power brick
An external power supply enclosed in a rectangular block that sits outside the main device.
Rail
A main supply voltage line that distributes power or a common ground across a circuit board.