Right so here we go:

My rig:

amd x2 4200+ am2 @ 2436
MSI K9n platinum sli (nforce 570 sli)
2 x 1 gb OCZ dual channel ddr2 667
Ultra X2 modular 550 watt PSU
evga 8800 gt 512 mb


I updated the cpu fan from the stock to a Zerotherm BF-90, booted it back up today, for some reason had to re-activate XP, did all that. Then I noticed my DVD drive wasn't opening, so I opened the case and attempted to plug it in while the pc was on. I had done this many times before, but this time the molex shorted out and the pc turned off. It turned back on, but no post, no beeps, no visuals, fan just run at max speed (usually when I boot up they run at max for like 5 seconds then die down.)

I did the basic troubleshooting, cleared CMOS, unplugged everything unneeded, checked connections, nothing.

So what does it look like?

Consider the DVD drive toast. You applied 12 V to 5 Volt circuitry, and 5 V to the 12 volt circuits. The five volt circuits propably shorted out reflecting a short back into the 12v rail of the psu. Since you can not post with the DVD drive disconnected my first quess would be that the PSU was also damaged.
Two options try replacing the PSU, or if you have a multimeter to check the five and 12 volt lines. Fans on means there is voltage on the 12 volts but not that it is correct.

Added: There is also a posibility that you put a spike on either the 5, or 12 volt line. This spike would be passed on to the MB and/or other components.

About a month ago another individual did the same thing with the HDD. I believe he was lucky and only wiped out his HDD.

Tried new PSU, nothing, same old symptoms.

I know I killed either the motherboard or the CPU; the question is which?

I've got a feeling I spiked one of the auxiliary power connectors that are on my mobo, so maybe I could have killed both cpu and mobo?

I get no beeps, no cpu error, nothing.

Usually when the CPU posts, the CPU and GPU fans slow down from max, this isnt happening either.

Sounds like at least a dead MB.

Anyway to tell if the cpu is shot too?