New Build!

Hey ya'll!

Way back in late '08 ya'll helped me build the following:

HD 640G|WD 7K 16M WD6400AAKS
DVD BURN SAMSUNG|SH-S223Q LS
MB GIGABYTE GA-EP45-DS3L 775 P45
CASE ANTEC|SONATA III 500 BK
VGA EVGA 512-P3-N954-TR 9500GT
CPU INTEL|C2D E8400 3G 775 45N
MEM 2Gx2|GSK F2-6400CL5D-4GBPQ

It's been a great 6 years! Recently, I've had an issue with it turning on and then immediately back off. I've troubleshot the issue and bought a new power supply, cleaned fans with canned air, checked for faulty capacitors, to no avail! Since I'm not sure how else to proceed I may just replace everything but the HDD, DVD drive and possibly the case. I do some illustrating and animating in the adobe suite that are somewhat resource intensive, though nothing the aforementioned build hasn't delivered pretty well on. I'll keep my old monitor, mouse, keyboard and speakers, too. I guess I'd be excited to spend $500 or less. Thoughts?

Thanks in advance!

Have you looked at my page about First Boot Common Problems? There are some suggestions there on how to work a problem like this.
http://www.mysuperpc.com/build/pc_fi...problems.shtml