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Switching Power Supply Repair | Power Tester Guide
Dec
Switching power supplies, especially computer power supplies, must always provide accurate output voltages. However, even these precise power supplies can develop issues over time. In this tutorial, we focus on troubleshooting a switching power supply. You will learn how to power on a switching power supply and measure its output voltages using a power tester.
Common ATX Switching Power Supply Failures:
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No output or PSU won’t start
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Overvoltage or undervoltage on 12V, 5V, or 3.3V rails
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Blown fuses or damaged MOSFETs
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Faulty capacitors causing unstable voltages
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Overheating due to fan failure or dust buildup
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Short circuits on connected devices
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Ripple noise affecting sensitive electronics
In the video below, you can watch and learn the troubleshooting process in a practical way
Standard PC Switching Power Supply Voltages :
In this section, we have also listed the standard output voltages of ATX switching power supplies, which are the power supplies used in desktop computers.
Yellow wire voltage: +12V to +12.5V
Blue wire voltage: −12V to −12.5V
Orange wire voltage: +3.3V
Red wire voltage: +5V to +5.5V
White wire voltage: −5V to −5.5V
(This wire is not present in some power supplies, especially newer models.)
