I'm having the same issue and although I'm not sure of the cause, I've found a solution that has worked so far. This all started when I noticed that my machine would not shut down properly. I'd do a shut down and walk out of the room and come back hours later only to find that the machine is still showing the shutting down prompt or the screen is black but machine still "running". So I do a hard reboot and run into the same black screen after boot like the rest of you. One thing I noticed, after holding in the power button to shut down, is that the activity led where my Ethernet port is, is still lit up and flashing fast like there is activity. Machine shutdown and obviously PS plugged in. I'm not for sure if that is normal because I've just never paid attention to it. Well, I decided that to first, pull the plug on the power supply and second, hit the power button once. This is the kind of procedure that I've been instructed to do in the past on a CMOS reset. I'm thinking that pushing in the button after the PS is unplugged discharges the MB. Anyways, I plug the PS back in, LED on the Ethernet port is now off, and boom my pc boots like normal. I don't know if this will help you guys out but hell give it a shot.