try this be sure that your battery is full then connect blackberry to your computer then just watch it in 5 to 10 minutes be sure that your desktop manager is running
some blackberry i faced did not connect faster to pc i'am waiting 5 to 10 minutes before its connect to pc
I posted the fix for this a few weeks ago, but like most forum members I'm feeling lazy
so I'm not going to retype it or search for it but i assure you it is there..(search)