Shoutbox

First thing I'd try is the basics. Try changing the fuse in the computer's plug or simply try another computer plug lead. Chances are you can borrow a fuse from another device around your home (just make sure it is the correct ampage). If the fuse has blown and your PC has had experienced a sudden loss of power the noise can sometimes resemble a 'boom'.

If that doesn't fix your problem look at the power adapter inside your pc. Is there any visible sign of damage?