okay, so i recently payed 500 dollars to newegg to get all the parts so i could build my own computer. so i got the computer and put it together, but one problem the 550 watt power supply i bought when i clicked the switch to turn on it does nothing, the fan doesnt spin no lights light up nothing. so i unplug everything and try just plugging in a fan and seeing if the power supply even worked, once again nothing. so just recently i went to best buy with the power supply and asked them to tell me if my power works or not, so they plug just the main 24 pin in and turn on and sure enough the fan starts spinning then stops the starts spinning some more, but the main point is that it works, then he plugs in the 4 pin plug and trys the power again and it lights up, fan spins cosistantly and everything seems to work good. so i bring it back home and try again doing the same as him first only the 24pin and nothing then the 24pin and the 4 pin and of corse nothing so next i try to unplug the memory, sata, basically all the cables and try and still nothing, please can someone help me with this problem. i will put links to my computer i just bought below.
motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128333
graphics card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814131095
power supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817342015
hard drive
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148261
memory
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231122
cpu
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103272
thanks for all your help
motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128333
graphics card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814131095
power supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817342015
hard drive
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148261
memory
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231122
cpu
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103272
thanks for all your help