I take it the fuse is an internal one then?
If so the fuse details should from memory be stamped on the metal ends somewhere (you may need very good lighting to see it), I wouldn't start small and work up with it because
1: There are loads of different types of mini fuse (both in ampage* and if it's qucik blow, slow blow etc)
2: If there is a fault that caused the original to blow, you may end up putting a much higher rated fuse in and totally negating the reason for an internal fuse (killing something much more expensive than a tuppence fuse, when it doesn't blow).
*I think i've still got some rated at something like 0.03amp lying around from repairing SNES's.