PSU dead/blown?

Hey, i need to know if this means my PSU is dead. My computer was running fine, then I got a new case and took everything out from my old case and put it together in the new one. With the new case, I noticed that if i would even tap the case a little bit, the computer would turn off, turn on by itself and the fans would start spinning much faster and it wouldn't turn on properly. (no post, no video comes up). In order for me to fix this, I would have to unplug computer from behind and wait a bit and the plug it back up.

Well this was getting annoying so I tried to make sure everythng was plugged in right. I replugged everything nicely and then i used a screw to tighten my video card in its place. This is where the big problems started. After i did that, I turn the computer on, it made a weird sound for a bit and then turned off. I tried turning it on again, nothing. I took out the screw, and nothing. I unplug it from behind and replug it and when i turn it on, the fans spin for about half a second (LED lights turn on for half a second) and then the computer turns off. If i want to see any power, i have to unplug and replug and again only get half a second. I can do that forever.

Is this PSU dead?



Specs:

E2180 2ghz @ 2.8ghz

3GB OCZ DDR2 800mhz (2x512mb 2x1024mb)

Geforce 7950GT OC

PSU: OCZ StealthXStream 500W

 

I tried putting in a generic PSU that I had laying around, and looks like the same thing happens. Does this mean motherboard is dead?

 

What's the mobo? This program can tell you:

http://www.cpuid.com/pcwizard.php

If the psu was dead, it wouldn't power on at all. It MAY be faulty. If you tap the pc and it goes out, I think there may be a short-out. You can confirm that by building the barebone on the mobo box. Short the power switch jumper with a pencil/ball pen.

If it still does that outside the case, clear cmos & try each stick of ram in each of the slots until you get the pc to post, go to bios, load defaults, increase ram voltage to specs. i.e. 2.1v. Look up your ram specs on the web.

 

Another thing I did. I took out the motherboard, unplugged all unnecessary things (hd, dvd). I set the motherboard on a box, plugged in the main power, the 4pin power thing and my video card, nothing else (except power switch to case). I put in one ram stick and again it turns on for a split second and turns off. I didn't get a chance to try every ram stick. The motherboard is a Gigabyte G965P-S3. I'm not sure what else to do or try.

 

4/8-pins = cpu power
20/24-pins = mobo power
6/8(new)-pins = pci-e power

Do try every stick in every slot. It's the only way to make sure it's not the ram.

 

When you put the motherboard into the new case,

did you set it up on the standoff pillars/nuts/posts?

What happens if you reverse all the changes, i.e replace everything back into its old place in the old case?