YUMHI12 :
MOBO is ASUS M5 A97 LE R2.0. PSU is EVGA 500w 80+ Bronze
Need the CASE not the power supply.
The power supply has one maybe two basic connections to the MOBO that, if not connected properly, will sizzle and fry your machine or yield no activity whatsoever; so I doubt the PSU is the problem here.
The case wiring is probably mismatched or missing.....will try to find you a nice diagram to go by. Need case model and brand though!
UPDATE: Look at the following link. See the twisted pair cables that are brightly colored red-white, green-white and blue-white? That's what you need to check.
http://www.pcgameware.co.uk/images/Asus-M5A99FX-PRO-R2.0-Installed.jpg