Why is mouse not working after dropped on floor?

Since we don't have any teardowns and internal information about this mouse seems to be scarce, you may have to play pioneer in figuring out how to open up this mouse and diagnose the problem.

First thing to do is open it up. From what I've seen, most Logitech mice are opened by removing the little glider feet which cover screw holes containing Philips screws. I'd suggest getting it open then looking around the inside for parts or connectors that are obviously disconnected, broken or out of place. We can help if you post pictures of what you find once you're inside.

Adding images to an existing question - iFixit Repair Guide