Beeps and wont boot up

Hello,
I recently dropped the computer keyboard.when i went to start my computer it just beeped about 7 times and my screen stays black like is in sleep mode.i unplugged the monitor to see if self test worked and the self test screen is working but thats it.also sounds like the hard drive is trying to work but it wont.tried restarting and hitting f2 or f12 and still not working.can some1 help.its a dell e310 desktop computer.also the numbers 3 and 4 stay lit up on the tower.