My DeepCool power supply is not powering on. How can I determine if the power supply is defective?

The most common way to test if your PSU is defective (once you have verified the power outlet is getting power, the power cable is good, and the power switch was "ON" were not the issue) is to do the Paper Clip Jump test. This involves completely unplugging everything from a modular PSU except for the 24-pin ATX cable, short pins 15 and 16 with a paperclip on the 24-pin connector, plugging the power cable into a power outlet, and switching the power switch on. If the fan spins, that is usually a sign that the PSU is likely working. If the fan doesn't spin, you more than likely have a defective unit, and might need to request an RMA.