Hello. I am a small systems builder and have had a few boards with similar post codes. They have all had to do with the Intel chipset that controls the USB. The last board I fixed was the Bluetooth module that comes with the extreme version. It caused the bios to not post at all. There was no video on screen except a cursor in the top left. As soon as I disconnected the Bluetooth module the system booted. Prior to this discovery I had tried all the other advice given on the forums. I had also done a bios recovery with the latest .BIO file. Other DX58SO2 boards I have fixed had similar problems but with other devices hooked to the chipset. Each throws a separate code. Some were ram issues, some USB drives, Some Media readers etc... The best thing I can tell you is to disconnect every device from the internal and external ports. install one hard drive, 1 video card and 1 keyboard. Reset the bios to default. If all else fails and it wont post, try a bios Restore from a flash drive. Turn off and un-plug computer. Wait until all capacitors discharge about 20 seconds. Remove the jumper from the bios reset header on the motherboard. Do not place it on pins 2-3, it needs to be removed. On another computer download the latest recovery bios for the motherboard and place it on a flash drive. Place the file in the root, not in a folder, use a clean flash drive with nothing else on it just to be safe. Plug the drive into a USB 2 port on the back of the motherboard and turn the computer on. The flash drive does NOT need any other files on it, only the .BIO file. You may not see anything on the screen, wait 5 to 10 minutes just to be sure it has completed. Once finished, turn off the system and replace the Bios on-board jumper cap on to the 1-2 Normal position. Power on the system. If you need any other help reply to post and ill see if I can help you. Good luck.