Flickering On and Off

Here's my setup.

Core i5 2400 @ $190
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115074

Asrock H61M U3S3 @ $75
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157236

EVGA GTX 560 -KR @ $190
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130660

GSkill 2x4GB 1333MHz @ $60 with promo code EMCKDKA29 (ends June 15th)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231422

Western Digital Caviar Blue 500GB @ $44
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136073

XFX Core Edition Pro 450 @ $55 ($45 after mail in rebate)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207012

Problem:

So it all started when I reformated a while ago. I would turn on my computer and it would flicker on and off in 2 second intervals until I force shutdown. The only way to fix it is to reset bios by taking the battery out. Once I do that it will turn on no problem. If I try to turn the computer on right after I shutdown it usually has no problem, but the problem arrises when I've shut it down all night and come back to turn it on the next day.

Note:

I'm kind of a hardware noob and my buddy built the pc for me.