dell inspiron n4050 hang on boot start up (dell logo on 50%)

Hi

1 yr old dell inspiron n4050 hang on boot start up on dell logo at 50%. it was working fine yesterday all i did is watch movies.

unfortunately i cant get into bios set up since f2/f12 are not working when it start to hang.

i did a series of first aid like removing battery for a day and putting it back the next morning (it did  not work)

holding the power button for the sec. then re opinging it again (while holding power and fn) did not hear any bip bip sound

i've tried removing the dvd burner, hard drive, memory card (all i left attached is the mother board it self , still hang on dell logo at 50%)

is this bios problem, can i still save my laptop if i made bios reprogram?

thanks for the help