For power supplies with different positioning, the number of output wires varies, but they all rely on the nine colors of flower green: yellow, red, orange, purple, blue, white, gray, green, and black. All sound PC power supplies have these 9 colors of wires (currently mainstream power supplies omit white wires).
Yellow
The yellow circuit should be one of the most common types in the power supply. With the addition of CPU and PCI-E graphics card power components, the+12V function plays a crucial role in the power supply.
+12V has always provided power for the spindle motor and seek motor of hard drives, optical drives, and floppy drives, as well as providing operating voltage and logic signal levels for ISA slots and serial devices+ When the 12V voltage output is abnormal, it often causes unstable disk reading performance of hard drives, optical drives, and floppy drives. When the voltage is low, it is manifested as severe disc picking in the optical drive, an increase in logical bad sectors of the hard drive, frequent occurrence of bad sectors, and system crashes, making it difficult to use normally. When the speed of the optical drive is too high, it is easy to lose control and cause disk explosion. The hard drive shows stalling and spinning. At present, if there is a shortage of+12V power supply, it will directly affect the performance of PCI-E graphics cards and the CPU, causing crashes.
Blue
-A voltage of 12V is used to provide logic judgment level for the serial port, requiring a small current, usually below 1A. Even if the voltage deviation is too large, it will not cause faults because the logic level 0 level has a wide range from -3V to -15V.
Red
+The number of 5V wires is equivalent to the yellow wires, and the+5V power supply is the working voltage provided to the CPU and integrated circuits such as PCI, AGP, ISA, etc. It is the main working power supply in computers. At present, CPUs use a hybrid power supply of+12V and+5V, and the requirements for it are no longer as high as before. Just in the latest Intel ATX12V 2.2 version, the+5V power supply capability has been strengthened, enhancing the power supply of dual core CPUs. The quality of its power supply directly affects the stability of the computer system.
White
At present, there are few commercially available power supplies with white wires. White -5V is also used to provide a judgment level for logic circuits, requiring a small current that generally does not affect the normal operation of the system and is basically optional.
Orange
This is specifically designed for the ATX power supply to provide power to the memory. In the latest 24 pin main interface power supply, emphasis has been placed on strengthening the+3.3V power supply. The voltage requirement is strict, the output is stable, the ripple factor is small, and the output current is large, above 20 amperes. Some mid to high end motherboards use high-power field transistors to control the power supply of the memory for safety reasons, but this tube may also burn out due to memory insertion. The platform uses+2.5V DDR memory and+1.8V DDR2 memory, and voltage conversion circuits are installed on the motherboard. Purple:+5VSB (+5V standby power supply) (standard range:+4.75-+5.25) The ATX power supply provides+5V 720MA power to the motherboard through PIN9. This power supply provides power for WOL (Wake up On Lan), power on circuits, USB interfaces, and other circuits. If you are not using functions such as network wake-up, please turn off these functions and remove the jumper to prevent these devices from drawing current from the+5VSB power supply terminal. The power quality of this output directly affects the standby power consumption of the computer, which is directly linked to our electricity bill.
Green
Control the power supply by voltage level. When the signal level of the port is greater than 1.8V, the main power supply is turned off; If the signal level is below 1.8V, the main power supply is turned on. Use a multimeter to test the output signal level of this pin, which is generally around 4V. Because the voltage output by this pin is at the signal level. Here is a preliminary method to determine the quality of a power supply: use a metal wire to short-circuit the green port and any black port. If the power supply does not respond, it indicates that the power supply is damaged. Nowadays, many power supplies have added protection circuits. After short circuiting the power supply, if there is no additional load, it will automatically shut down. Therefore, everyone needs to carefully observe the momentary start of the power supply
Grey
During the startup and shutdown process of the ATX power supply, when the motherboard sends a PS-ON startup signal to the power supply, the power supply needs to wait for all its output voltages to stabilize before sending a safety signal to the motherboard. The motherboard then starts the actual startup process based on this safety signal, which is commonly referred to as Power Good (PG). Generating a PG signal is not simple. It requires the ATX power supply to send the PG signal to the PG terminal of the motherboard within 100-500ms after the output voltage stabilizes.
