Whenever I turn it on, it always beeps 4 times, then a break, 4 times again, then a break and then 3 times.
Before that, the laptop fell on its side off of a metre and a half desk. The screen was very dark and I couldn't see a thing. It got fixed and was working fine until my friends and I accidentally whacked it. Then it started to do the things at the beginning of this post.
It so might have been that the circuits were probably damaged from the fall.
Now, the 4 beeps indicate a memory issue - download the service manual here - http://dell.to/20ZyccH - remove and reseat the memory modules and check. Try each module in each slot. If you find a bad module, replace it. If nothing works, replace the motherboard.
If there is no warranty, then you could contact our team to get a quote for a paid service call - http://dell.to/1vnT6CQ