Originally Posted by devvfata1ity
^no unfortunately not. Right now waiting for the TX850V2 to arrive and hoping that it will solve the problem. All I can surmise is that since the PSU is not from a reputed OEM it might have so-so capacitors that might have gone below spec due to capacitor aging. So when I first installed the HD6950 after taking out the GTX 260 may be the additional power requirement caused a crossload issue with all the fans & HDDs connected putting more stress on the PSU and causing this issue.
That's a very logical assessment. It sounds like you have it well in hand.
My approach when something like this happens is to try to isolate the issue, removing one possibility at a time.
So swapping PSU is a good choice to rule that out. Next to test HDD/controller failure, boot onto a live CD or USB, but with something that will use CPU, RAM, etc. such as Linux, TRK, or Hirem's boot disk. As we already discussed you can also try swapping RAM out one chip at a time, but since you tested that it's probably okay.
Finally, once you think hardware is all sound go for the re-install and you should be fine. It sucks that this happened to you guys, sounds like a nice build. I'm sure you'll get it going ... it's just frustrating when a roadblock like this stands in your way.