How to quickly analyse the failure of the switching power supply and repair it in a timely manner
Overhauling ATX switching power supply, starting from +5VSB, PS-ON and PW-OK signals to locate the fault area is a proven method in quick overhaul.
5VSB, PS-ON, PW-OK control signals
ATX switching power supplies rely on a combination of +5VSB and PS-ON control signals to switch the power supply on and off. +5VSB is for the host system in the ATX standby state of the power supply, as well as open and close the automatic management and remote wake-up communication and liaison related circuits of the power supply, in the standby and controlled start-up state, its output voltage are 5V high level, using the purple line from the ATX plug 9 pins lead. PS-ON for the host to open and close the power supply or the network computer remote wake-up power supply control signals, the different models of ATX PS-ON is the control signal for the host to switch on and off the power supply or for the network computer to wake up the power supply remotely. When you press the host panel POWER switch or to achieve the network wake-up remote power on, controlled start PS-ON by the motherboard electronic switch ground, use the green wire from the ATX plug 14 feet input. PW-OK is for the motherboard to detect the power supply good or bad output signals, the use of grey wire led by the ATX plug 8 feet, standby state is zero level, controlled start voltage output stabilised for 5V high level.
Offline power detection ATX power supply, the first measurement in the standby state of the PS-ON and PW-OK signal, the former is a high level, the latter is a low level, in addition to the output of the plug 9 pins +5VSB, do not output other voltages. Secondly, the ATX switching power supply artificial wake-up, with a wire to the ATX plug 14 feet PS-ON signal, and any ground (3, 5, 7, 13, 15, 16, 17) in a short, this step is the key to detect the ATX power supply from standby state to wake up for the start of the controlled state, at this time, the PS-ON signal is a low level, PW-OK, +5VSB signal for the At this time, the PS-ON signal is low, PW-OK, +5VSB signal is high, ATX plug +3.3V, ±5V, ±12V output, switching power supply fan rotation. The above operation can also be used as a method to verify the offline power-on of the ATX switching power supply.
