Pc was shutting offafter a few sec. so I replaced power adapter. Now pc runs but still has black screen. Keyboard is blinking twice every few sec. indicating corrupt bios. I tried fix: Win+B then press power for 1 to 3 sec. Pc came on then powered itself off then came back on and still black screen. Is there anythingn else I can do? I don't know anything about the bios. Will changing hd help?