Belta was saying he was looking for a replacement for his G9 Logitech mouse which unfortunately is no longer being made. Most of the problems with these mice are due to cords fraying or microswitches that don't click like they should. I came across a number of articles on replacing cords (which can be found on ebay) and also on replacing the Omron Microswitches which can be found on ebay or a number of electronic supply stores. Here is one vid showing replacement of the switches.
https://www.youtube.com/watch?v=MO2izhYxGhk
Other vids on replacing the cable are even easier as the cables have a connector which plugs in inside the mouse.
https://www.youtube.com/watch?v=MO2izhYxGhk
Other vids on replacing the cable are even easier as the cables have a connector which plugs in inside the mouse.