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Frequently Asked Questions - Tech Support

What power supply do I need for my computer?
Go to our Power Supply Selector.
Why can't I use a standard ATX power supply in my Dell computer?
They are mechanically and/or electrically incompatible. Our Dell power supplies are custom-built for specific Dell models. See the Dell Selector.
If I were to upgrade to a higher-wattage power supply, will it hurt my system?
Absolutely not. Your computer will only draw the amount of power it needs. The extra capacity of a higher-wattage unit will improve the power supply's operating range, regulation, hold time, ripple, cooling, and MTBF. See Power Supply Myth #1
How can a user compare wattage ratings among PSU manufacturers?
In order to compare wattage ratings, a consumer needs to know if the manufacturer's rating is for continuous power or peak power. If "continuous" is not clearly stated on the label or in the specs, assume the rating is peak and deduct 20% for an estimate of the true wattage.

A consumer also needs to know if the wattage rating is at room temperature (25° C) or at operating temperature (40° C). If the wattage rating in the specs does not clearly state the full-load temperature, assume the rating is at 25° C and deduct 20% for an estimate of the true wattage.

If the wattage rating is for peak power at 25° C (both de-rating conditions exist), deduct 40% for an estimate of the true wattage.

What are the components that draw the most power and force users to upgrade their PSUs? (e.g. dual-core chips, top graphics cards, drives)
Video cards draw the most power and are the primary reason for PSU upgrades. All three components draw from the 12 volt output, so the 12V rating is by far the most important spec today.
My computer is dead. Is there a way to check my power supply?
Go to our ATX Power Supply Troubleshooting Guide.
My computer will turn on, but will not boot. Could it be my power supply?
Check the output voltages with a voltmeter. If they're all within 5% of nominal (5.0V, 12.0V, etc), the problem is probably motherboard or software related. To confirm, swap-in a spare power supply (known to be good).
My computer locks up. Could it be my power supply?
This is most likely a motherboard, video, or software problem. After ruling out these causes, try a higher-wattage power supply (known to be good).
My computer intermittently shuts off. Could it be my power supply?
Power supplies have a circuit called Over Current Protection. If a component in the computer malfunctions intermittently (make sure cards are seated properly), it will draw excessive current, trip the OCP circuit, and shut off the computer.
My computer is noisy. Is my power supply bad?
First, determine the primary source of the noise. The CPU fan, video fan, case fans, and hard drives may be producing far more noise than the power supply itself. Next, isolate the noise from the power supply from the other sources. If the noise is the sound of rushing air, it's normal. And, in a heavily loaded system, the noise can be quite noticeable. If the noise is a grinding mechanical noise or a high pitch electrical whine, call for further assistance.
Are the voltages indicated by my motherboard monitoring software accurate?
Usually not. To check the accuracy, use a high-quality voltmeter to measure the +5V (red) and +12V (yellow) on an unused drive connector while the computer is running. Note: the GND lead from the voltmeter goes to a black lead on the drive connector.
How do I test my power supply before installing it?
Follow steps 4-7 of our ATX Troubleshooting Guide. For a more complete test, order our ATX Power Supply Tester.
Can I mount my power supply upside down?
The orientation doesn't matter as long as the power supply's fan is blowing air out the back of the computer case.
Can my power supply be used in Europe (230V input)?
Yes. All our power supplies have PFC, which enables the supply to run on any input voltage between 90VAC and 264VAC (no switch required).
What exactly is PFC? What are the advantages?
Power factor (PF) is the ratio of true power (watts) divided by apparent power (volts x amps or VA). A standard power supply has a power factor of .7, while a supply with active power factor correction (PFC) has a PF of .95-.99. A power supply with PFC is better able to convert current into power. This results in lower peak current and lower harmonic current, putting less stress on wiring, breakers, and transformers.
Can I customize my power supply?
Go to our Custom Options page.


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