Can you tell from looking at the fuse whether it has blown in the middle of the loop of wire inside it, or at one of the ends? This type of fuse normally blows in the middle when it is overloaded, however occasionally they are badly manufactured and fail at one end.
A common reason for the VIN fuse blowing is connecting the VIN power the wrong way round (I have done this myself!). However, if the blue VIN LED lights up, then VIN must be connected the right way round.