Last week my laptop wouldn't boot. I figured it was my hard drive (as I ran a pre-boot assessment saying so) so I didn't think twice about buying a new one since I been wanting a bigger one anyways. Well I still have the same problem. It won't boot from the hard drive. I booted from usb drives and cds but it won't boot from a hard drive. Everything runs great when booting from a usb drive (I have ubuntu installed on the thumb drive). It just flashes the under line character( _ ) on the top left of the screen over and over. The pre-boot assessment now runs fine with no problems. 

Any ideas what it could be? I even tried the hard drive in another computer and it works fine. I read somewhere that it might be the motherboard, but wouldn't that stop it from booting at all? A few weeks ago I flashed to a older bios (A09) because the A12 version wouldn't let me charge my battery. After flashing down it charged just fine. It worked just fine after I flashed too, well for a week or two. 

Thanks for your time.