no use :/ i just discovered that the red wire connecting the two terminals has been cut away from the positive terminal
you can see it in this
https://gullfoss2.fcc.gov/eas/GetApplicationAttachment.html?id=684680
second page
i just went through my dad's tools and supplies for a thin copper cable to reconnect the terminals, because it's impossible to solder it without opening the mouse in half as in the picture
any (other) suggestions ?