PSU Problem? ?

[gartersnake184]

Pc specs

i5 3770k 4.40Ghz
Gtx 770 MSI Video Card
8 gb ddr3 (can have max 32gb)
Asus mother board Z87-A with USB 3.0
1 tb hard drive
Cool master 750 power supply
WINDOWS 8
My computer won't turn on. But once I plug the power cord in amd flick the switch on, a green light on the mobo comes on. Does my psu need to be replaced?

 

[Vic 40]

Other steps,
http://www.tomshardware.co.uk/forum/261145-31-perform-steps-posting-post-boot-video-problems