Hello

I have a 6770 ultegra front derailleur on one of my bikes which has worked fine for years...
Until i disconnected the cable and then tried to plug it back in to the derailleur again.
I'm not sure if there's dirt inside but i just can't get it connected (and clicked into place) again even with the etube connector tool and actually damaged the plastic ends of 2 cables in the process.

any tips?