Can't get device to hotsync

First thought is that the cable has become defective - they do go wrong.

Assuming the visor is fine other than when hotsyncing, I suggest you reinstall the Desktop manager and hotsync manager on your PC or Mac, HAVING BACKED UP ALL FILES of course.

Sometimes the managers get corrupted and cause problems. Try that first, then check cable and finally a hard reset, assuming you have hotsynced recently and so won't lose loads of information.