BleepingComputer.com: Computer Not Booting After Upgrade

Alright, I just upgraded my computer and I can't seem to get it running. First I'll begin with specs.

Before upgrade (upgraded parts preceded by asterisk):
ASUS M2N32-SLI Deluxe/Wireless Ed.
*AMD Athlon 64 X2 4200+
*2x 7950 GT 512 SLI (OC'd a little)
Cooler Master 1kW PSU
3 GB Ram (2 GB are Corsair XMS2 DDR-800... then 2 512 sticks of older ram)
300 GB SATA HD
think that's about it...

As for the upgrades:
AMD Athlon 64 X2 6400+ Black Ed.
EVGA 8800 GTS 512 (G92)
150 GB Raptor (not initially installed)
ASUS Silent Square Evo (CPU cooling)

OK, now for the problems. I began by installing the processor, graphics card, and CPU cooler. When I turned on the computer, everything came on (all the fans, lights, etc.), but didn't progress past the screen that says "Press delete to enter setup". When I tried to enter setup with Del or boot menu with F8, one of two things happened: 1) with HD plugged in, if either was pressed it would say "Entering *whichever*....." and sit there doing nothing, or 2) with HD NOT plugged in, it would enter either one normally but not detect the HD (as expected since it's not plugged in lol).

At that point I thought my old HD got messed up, so I decided to install my new HD. After it was installed, I could no longer enter boot menu or setup whether it was plugged in or not.

I then tried putting my old graphics card back in: no change. Then I put my old processor back in: still no change except now the computer shuts itself off randomly and without warning (sometimes after a minute and sometimes after a few seconds).

One thing to note is that I used a small magnetic screwdriver to take out the mobo (cooler installation... old cooler didn't use a universal clip), although I read that this should not hurt the mobo. Also, my DVD ROM drive no longer seems to work (but my DVD RW drive still does).

I've also tried resetting the CMOS. I'm thinking my mobo somehow went bad (hope I don't have to get a new one...). My brother also suggested that it may be something with the bios and I might have to flash to a new version.

Anyway, that's my issue. Hopefully it can be resolved without too much trouble.
Thanks in advance for any help.

It could be your power supply what model cooler master is it? With no HDD plugged in will the computer POST (will it get past the system test and tell you there is no HDD installed)?

The CM model I have is the Real Power Pro1000 RS-A00-EMBA.

As for the POST, it gets past it every time and ends up on the BIOS screen (displaying "press del to enter setup"), never displaying any error messages even with the HDD disconnected. Would it give me the error message after the BIOS screen if it could get there?

Giving you the pres del to continue means there is a problem IE no HDD detected. It seems like its getting past post but I would still check the power supply first. It could be the MB, Did you unplug the power supply from the wall outlet before removing anything?

Yeah, I unplugged the PSU before removing anything. The PSU seems to work (all the lights, fans, etc are on/running), what would I do to check it?

did the old cpu cooler use a backplate?

Well it seems the problem is solved now. It's quite embarrassing, but somehow the power to my DVD drive was unplugged and I overlooked it (I honestly don't remember unplugging it... had no reason to do so). So I plugged it back in and everything booted up fine.

I'd like to thank you for your help on the issue and for your time. The new stuff's working great so far now that everything's plugged in correctly.

Thanks again!

glad you got it working. Congratulations on the upgrade