I would recheck all my connections, cards and memory. Did you check all the standoffs, to be sure there are no extras, and they align up to the MOBO holes?
If all else fails, you could start from scratch. People always ask me about building their own system, so I wrote this up, to explain the best approach, that I use.
To start with, here are a few tips that may help you in your endeavor. First, if you don’t have a ground strap, then you will need to discharge, any static charge that you hold, by touching the computer case, or any metal object. Before handling any static sensitive objects CPU, memory sticks (dims), motherboard, and expansion cards, be sure to discharge yourself first.
• If you are building your own computer, first try and put it together outside the case, this has a couple advantages, the first being saving your sanity. You want to start with the bare minimum, that being the motherboard, CPU, and the power supply. You may need a front panel speaker, if there isn’t a beeper, on the motherboard, and also the on/off switch, from the computer case, plugged into the motherboard’s front panel terminals. Now, when you turn the computer on, you should see all your fans spinning and hear a bunch of beeps, so you now know that the motherboard, power supply, and the CPU all work.
• Now, this is very important, before going any further, unplug the power cord, from the power supply. Be sure to discharge your static, and now, install one stick of memory, I know, you want to put them all in, but only one stick, for now. Plug the power cord back in, and turn it on, you should hear a series of beeps (1 long 3 short), as the computer searches for the video card. Ok, turn it off, and unplug the power cord again, from the power supply
• Now, discharge yourself and inset your video card, then connect your monitor to the video card. Plug the power cord back in and turn it on. You should get the Power On Self Test (POST) one beep. Then, you should get a display, on your monitor screen, showing your basic boot screen, and a boot disk error, because you don’t have any drives installed. Up to now, if you have the monitor display, and the disk error, your system is sweet.
• Now, start putting these components, in the computer case, but first, be sure to look at the number, and the placement of the standoffs. Make sure you don’t have more standoffs than you need, and they all will line up with the mounting holes, on your motherboard. Sometimes, a standoff will be slightly leaning too far to one side, and may have a tendency to short out a circuit on the motherboard. In the case of the misaligned standoff, maybe try persuading it over in the correct direction with a needle nose pliers, or use a small piece of electrical tape around that mounting hole, on the motherboard.
• Once you have these components installed, in the case, and have your boot display, on the monitor, along with the disk error, then you know you have a good start.
• Now, install the drives, partition, and format your hard drives, setup the BIOS, install the operating system, and add the remaining hardware and drivers. Now. go take your computer for a spin around the block.
This may, or may not be of any help to you.
I was just wondering, what size is your PSU? Your power supply may not be big enough, to push all the power that your new components add to the load.