I am actually worried my laptop is going to explode based on the noise. I updated drivers and bios yesterday and since then the noise it has been making sounds like it is going to destroy everything within a mile!

A loud buzzing that changes speed, pitch and pattern coming from the left hand side. It is intermittent but has started to affect the laptop by locking it or turning the screen black. 

I cleaned the fans with canned air but it almost seems worse. 
I have no faith in this laptop with everything that has already been replaced during the warranty so I am not surprised that now it is just out of warranty something really bad is happening.

Second Dell laptop and hoping the motherboard is not going in this one too!

anyone got any ideas before I sell this onto some other sucker and buy a Mac! 
thanks in advance 

Nicola