"Why does my G400s connect and disconnect randomly?"に関する回答There may be an issue with the mouse cable. Try replacing it according to this guide.
"Why does my mouse not move smoothly?"に関する回答There may be an issue with the mouse feet. Try replacing them according to this guide.
"The buttons on my G400s do not feel crisp when pressed?"に関する回答Grime is most likely preventing the button from functioning correctly. Try disassembling the mouse according to this guide and then clean the problematic buttons with rubbing alcohol.