How to Select Computer Power Supplies Using a Multimeter
There have been many discussions on the identification methods of power supplies in various newspapers and magazines, which can be summarized into three aspects: first, check whether the materials used in the power supply are excellent, whether the workmanship is fine, and whether the layout is reasonable. To be honest, this plan is somewhat difficult for others. Firstly, it requires implementers to have sufficient electronic knowledge; Secondly, in order to thoroughly examine the five organs and six lungs of the power supply, it is necessary to remove the power supply cover, which inevitably breaks the warranty seal of the merchant. Once the seal is broken, the merchant's warranty is automatically lost, and even if there is a problem with the power supply, DIY is necessary. I think many ordinary rookies are forced to become big shrimp in a desperate and helpless situation.
Second touch - refers to touching whether the wind blown out by the power fan is hot and whether the cover is hot to the touch after turning on for a period of time.
Three Smells - Smell whether the power supply emits a burnt odor after prolonged operation. The latter two are purely the accumulation of sensory experience, how can beginners make judgments without any experience?
Here, I recommend a method of using a multimeter to determine the quality of a power supply, which may provide some help for beginners. Firstly, of course, it is necessary to find a multimeter (preferably a digital one) and be able to use it. The voltage provided by the aTX power supply mainly includes 3.3V, 5.0V, and 12.0V. Among them, 12.0V is the main energy source for driving hardware devices, and the change is also significant after connecting more loads. Therefore, after connecting all the loads of the computer, choose an idle output head and insert the black probe into the black wire interface and the red probe into the yellow wire interface (to detect the 12V output voltage). After connecting all the connectors, you can start the machine for testing.
After booting up, we can see that the multimeter data is constantly changing until the system is fully started and stabilizes. Write down the voltage value at this time. Normally, it should be around 12V (approximately between 11.95V and 12.15V. If it is too low, it cannot guarantee long-term stable operation of large loads and has no expansion potential. If it is too high, it will cause the device to heat up and age prematurely). Then press the rESET key to restart the machine. At this point, it is important to closely monitor the numerical changes on the multimeter. If the voltage difference between the highest and lowest values during startup is not too large (within 0.3V), then this power supply is acceptable. If the pressure difference is too large, it indicates that the power supply has poor load capacity and should not be selected. I have personally encountered a 300W power supply that has a maximum value of 12.32V * low but only 11.73V, and frequently crashes during use.
Finally, observe the situation during use. Run various software and listen to music on the CD drive to get all the components of the machine running. Pay attention to the voltage at this time. If there is no significant fluctuation, you can choose it.
