wow, this is exactly like my situation. My rig (a8n32 sli-deluxe, opty 170, corsair 2x1050 3500llpro, 74gig raptor, 300gig seagate, zalman 9500, lian li pc65b, bfg 7800gtoc, seasonic 600w).
I went to work the other day, left my computer on...came back the computer was turned off. I started it back up and it got through the Asus screen and post messages, then just to a blank screen with a curser blinking in top left corner. It kept going the the blank screen no matter what i did...
I tried changing things in the bios, booting windows from a disc, booting from a floppy, cleared cmos, removed hard drives, ram sticks, tried different powersupplies, cddvdrom drives/burners, rma'd the mothererboard and got a brand new one, and still the same symptom. So the only thing i couldn't check was the cpu. So today i took it to a trusty repair shop and found out it was definatly the cpu.
It was a opteron 170, had been used for 3 months. I'm pretty sure it fell victim to a power surge, and i wasn't connected to a ups at the time. So i'll go through the rma process...you can rma OEM processors right?
Does anyone know if when your RMA is approved, if you get a brand new processor with new steppings, or do they ship you the same one back.
So this may very well be the same issue you have. Sorry bro.