Laptop, shuts down after powered up (Fan go's on)! Dell 1545?

hi,

i recently dropped my laptop down the stairs, i smashed the screen, and i tiny bit of the casing, the problem i am have it that i will turn it on, the fan will run of around 5seconds and then go off! and nothing happens on the screen. the power button that means it is on, is still working, but i never get bios or anything. any ideas what might be broken ?

It's a DELL 1545 inspiron, i would like any help you could think off

things i have tried:

swapping the ram around.
installing new screen, (used my m8s from his laptop, same type)
booting without ram --- this makes it continuously beeps ?


thanks oli