Mac Pro A1289 (2009); 2.66 Quad; 16GB RAM; OSX Mavericks; 2TB & 640GB HD; GT 120 Vid Card & GTX 570. I was formatting and installing my 640 hd for bootcamp. I did the craziest thing in the world; pulled my plug from the wall. Why, wtf was i thinking? I have my laptop plug there and was not even using my brain to determine the difference. Booted up my MP again in the GT 120, it chimed, stalled on grey screen, went black then said 'not boot disk detected, please insert boot disk' or something of that nature. I couldn't open my tray because it wouldn't detect bluetooth (now i remembered why i hated bluetooth with my mac mini years ago). I don't have an apple corded keyboard. I used a regular cheap keyboard to try to boot into recovery/other drive by pressing alt; didn't detect anything, stayed on grey screen. SO, I took out my drives [and my GTX just in case], but focused on my 2TB since i was going to use that primarily. Put it on my MBP, formatted and reinstalled Mavericks; even went so far as to set it up so when i plugged it back in the MP it would just work. Showed the home screen and looked pretty. So now i went to put it in my MP cause its ready to go....NOPE, something else is wrong and I don't know what. Booting in the MP, it loads the HD, chimes, goes to grey screen, then it goes to black. But Now the black screen shows an insertion line, but i cant type anything. it also pulsates in a subtle manner, like 1 time, 1 time, 3 times, 1, 1, 3, 1, 2, 1, 3...its repetitive, but random in its order. Im going to format and try my 640 HD and see if that works. if it doesnt, I have no idea what else to do. I read around that if i chimed, that means the Board is ok..so im trying to be optimistic that i just have to work on my HD's...but i dont know.. maybe remove and replace the battery? Any help would be very much appreciated.