Choosing a computer power supply with a multimeter
There have been many discussions on the identification methods of power sources in various newspapers and magazines, which can be summarized as follows:
Take a look - check if the materials used for the power supply are excellent, if the workmanship is fine, and if the layout is reasonable. To be honest, this plan is somewhat overwhelming. 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 will inevitably damage the seller's warranty seal. If the seal is broken, it will automatically lose the seller's warranty, and even if there is a problem with the power supply, it will have to be DIY. I think many ordinary rookies are forced to become prawns in this desperate and helpless situation.
Second touch - refers to touching the power fan for a period of time after turning it on to check whether the wind blown out is hot and whether the cover is hot to the touch.
Three Smells - Smell whether the power supply will emit a pungent odor after prolonged operation. The last two are purely the accumulation of emotional experience. How can beginners make judgments when they have no experience to speak of?
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 important to find a multimeter (preferably a digital one) and be proficient in using it. The voltage provided by the aTX power supply mainly includes 3.3V, 5.0V, and 12.0V, among which 12.0V is the main energy source driving hardware equipment to work, and the changes are also significant when more loads are connected. Therefore, after connecting all the loads of the computer, choose any idle output head, 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, the machine can be turned on for testing.
After booting up, we can observe that the data from the multimeter is constantly changing until the system is fully started before stabilizing. Record the voltage value at this time. Normally, it should be around 12V (approximately 11.95V to 12.15V, too low to ensure long-term stable operation of large loads, and without expansion potential. If it is too high, it will cause device heating and premature aging). Then press the rESET key to restart the machine. At this point, it is important to closely monitor the changes in the value of the multimeter. During the power on self-test, the multimeter value will reach a low point. Record the voltage value at this time. If the voltage difference between the highest and lowest values 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, with a maximum value of 12.32V and a minimum value of only 11.73V, which frequently crashes during use.
Finally, observe the situation during use. Run various software and listen to music on the CD drive, allowing all components of the machine to operate. Pay attention to the voltage at this time, and choose it if there is no significant fluctuation.
