TY. Will check that as well, and maybe your device as well.
I actually have 2 of those trackballs. First one I bought after about 4 yrs one of the 2 boards inside died so I went and bought another one (they were $99 cdn each, $35 in the states at the time of purchase), it lasted about 4 yrs as well then one of the boards died. The best part was the boards that died were different in each so I pulled em apart and combined the working boards and have been using it since, total this device is about 25 yrs old now

