Well I have the same PSU, Strider 500watt, I have the same problem, when I power on my PC it turns on for a sec and then turns off again, thankfully nothing except the PSU itself is burnt, hopefully eveyrthing will be fine once I get my new PSU delivered
Could be that you have the same problem :| but since ur GPU got burnt, it could be a GPU problem too, if u have any friened or relative with a good PC (C2d etc) check with his parts and see what the problem is. As for ur GPU, Czone and Galaxy consider the warranty void if the GPU is burnt, they will instantly blame u for voltage fluctuations and loadshedding issues
bad luck