Hafi 0 Newbie Poster

Hi, I have a Acer 5310 which has developed a problem where upon startup the splash logo appears but then the screen goes blank/grey.
I can get into Bios using F2 where everyting seems as it should be, but even after choosing default settings I still get the same problem. No other buttons work such as F8, F10 etc.
I also cannot boot off a cd, I have also tried it on an external monitor but still no luck.
Can anyone help?