HELP!! boots to white apple screen then turns off!

help!!

My finder was not responding so i had to turn it off, and when i tried to boot it back up it got to the white apple screen, it flashed a small grey horizontal bar at the bottom of the white screen a few times then turned itself off. it keeps doing the same thing now...

any help would be much appreciated..

heres the same build as mine: Hackintosh Build: Build a Mac OS X capable computer in a few easy steps… | MatthewMintun.com ... fessional/