is my cpu dead?

So i finally got my shiny new core 2 quad q9550 to replace my core 2 duo e6400, and after I get everything in, it's not working. It boots up fine, I can go into the BIOS and change the settings around, I can see that the temperature is holding steady at 49 C, and it is recognized by the motherboard. but as soon as I try to load up my operating system, the whole system just shuts off with no warning. I get the same result when I try to boot up with the windows cd, or with ubuntu on a flash drive. Is the cpu a dud? or could it be something else?

to be honest i think i'd be looking elsewhere, it wouldn't even boot if it wasn't working, but wouldn't rule it out either. did you check your power supply was good enough to handle the extra draw of a quad core cpu compared to the dual??

I tried unplugging 2 hard drives and both of my optical drives, but it didn't seem to help at all, and now it just freezes up on the first splash-screen that comes up, so I can't even get into the bios. I'm going to try and put the old CPU back in to see if anything changes.

could still be psu, what are the specs of the psu anyway? also if it boots fine with old cpu, find out what bios version your running then check it with your motherboards site to see if it's compatible with the q9550, it might need a bios update before the cpu will work correctly, if it does need an update, update the bios with the old cpu installed then install the new cpu.

the power supply is 650 watts, which, according to a couple of power supply wattage calculators, should be enough for my system, it's a pretty new high end corsair power supply, and it works fine now with the old CPU back in, so I think i'll have to give it another try today and update the BIOS. I'll also try running it barebones without any unnecessary components.

I'm not sure what else to try, I updated the bios to the latest version, no change. I tried running it with only one hard drive, and I even tried putting my old graphics card in that draws a lot less power, but no change. It's really weird, it will run all day on the bios screen, but as soon as it hits the first loading screen for the operating system it shuts off with no warning. Is there some setting in the bios that I need to change? I couldn't find anything that seemed relevant, but I am not very well versed in tweaking bios settings.

Can you try an empty HD and freshly install Windows? I realize you may wish to use your present OS & configuration and simply swap CPU's… which should work. But since it isn't… Also consider running a small Linux live CD such as Puppy to see if you can get video, sound, online, etc.

I've tried running ubuntu from a flash drive, as well as trying to boot up with the windows disc, no matter what I do, it always shuts off shortly after the first screen for the operating system comes up. I can get into the bios and change settings around to my hearts content, but nothing seems to make any difference. I have also tried using a hiren's boot cd, and none of the diagnostic tests that I ran came up with anything out of the ordinary. it's pretty baffling, because if the CPU was a dud, i wouldn't think that I would be able to even boot it up period.

Bootable CD's such as those you mention are not dependent upon the HD booting sequence. By that, I mean the MBR. Once booted from the CD, the owner/user can poke around anywhere they like and it can appear to be no problem. But you seem to be having trouble when booting involves the Hard Drive pre-windows environment of master boot record. That's why I suggested a cleanly formatted HD, and then attempt to run your Windows installation media disk to produce and boot with a fresh OS. May not get you anywhere, but might. Best Regards

so far I've tried booting 3 different types of linux off of flash drives, and 2 different live cd's, ubuntu and suse, and with all of them, as well as windows, I get the exact same result, about 2-3 seconds into the first loading screen for the os, and it very abruptly shuts down without even a beep. I've tried it with and without the hard drives plugged in, with no difference either way. but as soon as I swap out the processor for the old one, everything goes back to normal. very weird. I think I may have to rma the new processor, but I want to rule out other possibilities so that I don't just end up with the same results when a new one comes.

I've tried running ubuntu from a flash drive, as well as trying to boot up with the windows disc, no matter what I do, it always shuts off shortly after the first screen for the operating system comes up. I can get into the bios and change settings around to my hearts content, but nothing seems to make any difference. I have also tried using a hiren's boot cd, and none of the diagnostic tests that I ran came up with anything out of the ordinary. it's pretty baffling, because if the CPU was a dud, i wouldn't think that I would be able to even boot it up period.

I have also tried using a hiren's boot cd, and none of the diagnostic tests that I ran came up with anything out of the ordinary.

This is the part from your prior posted report that made me wonder if the problem related to HD.

Since your statement indicates that diagnostic tests were performed, I was led to believe that they were actually being run via MOBO/RAM/CPU

But apparently not with your new quad CPU?

if not, then you may be in for an RMA.