@Dmaster
The Fuse is not the problem if one of the Axis' is working all movement would stop if it was the fuse.
It sounds like the cable is bad.
I personally have some of these:
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=49_91&products_id=88that way I can use a good Logitech PS2 Optical Mouse.
Just one option.
If you really want the original mouse to work again then you will have to remove the original cable, buy a new cable (Probably a Joystick Extension or Something of the like) Cut off one end and solder it into your original mouse.
Hope This Helps