ATX Power Supply and Wire Markings
The ATX power supply is the successor to AT power supplies. The ATX standard defines the shape of connectors, voltage, current levels, and how the power supply is turned on and off through signals from the motherboard. So, what’s inside?
Here is an example of a Tech Master power supply.
What interests us most are its wires. Why? This will be useful for a future project involving a workshop power supply 🙂
- YELLOW: 12V line
- RED: 5V line
- ORANGE: 3.3V line
- BLACK: GND (ground)
- BLUE: -12V line
- WHITE: -5V line
- PURPLE: 5V standby (operates when the power supply is connected to the computer)
- GRAY: Power good (checks if the power supply is working correctly)
- GREEN: Power on (used to start the power supply)
Connector Types:
Molex
RED+BLACK+BLACK+YELLOW
5V+GND+GND+12V
SATA
YELLOW+BLACK+RED+BLACK
12V+GND+5V+GND
20+4 PIN Power Connector
The pinout is described above the wire descriptions.
4 PIN CPU Power Connector
2x YELLOW+2x BLACK
2x 12V+2x GND
6 PIN PCI-E Power Connector
3x YELLOW+3x BLACK
3x 12V+3x GND
There are more types of connectors, such as FDD, 8 PIN, and 6+2 PIN PCI-E, but these are sufficient to understand what’s going on inside the power supply 🙂
