Power Supply Causes of No Power to the Motherboard
Sometimes the power supply is at fault for no power to the motherboard. One of the most common errors made by computer builders is failure to properly set the power supply to the correct voltage.
Notice that there is a little red switch recessed into the back of your power supply. Using this red switch, you need to set the voltage of the power supply depending on the country in which you intend to operate your computer. The United States uses the 110/115 volt standard whereas Great Britain uses the 220/230 volt standard. Using the wrong setting can cause damage to both the power supply and any of the components in your computer. To check your country’s voltage standard, check out Voltage Valet’s Directory of Foreign Electrical Information.
One of the problems you may encounter when buying a power supply is the industry’s focus on power supply wattage. The more components you have in your computer, the more wattage you will need to power all of these parts. Unfortunately, power supply manufacturers only tout their products’ wattage and fail to inform customers of amperes, the number of 12 volt rails within the power supply, and several other important factors. If your computer’s parts require 600-watt peak power and your power supply is just at or under this threshold, you are likely to experience intermittent problems whenever your computer tries to draw too much power.
Before you buy a new power supply, do the math to determine your computer’s needs. Start by adding up the peak power requirements of each of your computer’s components. Pay particular attention to the most power-hungry components such as the CPU, the video card, and the hard drives. Also, be sure your power supply meets the minimum amperes requirements for the total number of components in your computer. Failure to do so may not only create power problems, it can damage the components in your computer.