so i went on and tried to put the mx300 cable into mx310 because this one i care the least about, it worked, but it didnt work the other way around, so i took the mx500 cable into mx300 and it worked..

i would much rather tho have the mx500 working also and trash the copperhead if it would fit? dont want to get ahead of myself and destroy the mouse with the wrong cable...

Just make them fit. Replug the pins. Make it look like the ones from logitech. Change the order accordingly.

Like acid reptile said, you need to replug the pins and copy the colour sequence from the mx300 cable - any cable can be made to work and it's a < 20 minute job. You need to be careful you don't get the sequence wrong though, I managed to fry a DA black edition a while ago when I had no idea what I was doing :P it got to like 100+ degrees in 2 minutes and is dead to this day ;(

well mx310`s cable has the right color sequence but it has like a coil at the end and when in the mx300 it started to act up.. for now i have it working, when i have the time i guess im gonna try this so i have my500 working too