ok you may need to change your usb settings, it might be under settings/tethering. Also you may need drivers for your pc not sure ill look further into it for ya m8 
yep usb debugging try that also click installing of off market apps see if that helps.
Does the same usb work on the other phone? if so settings need to be changed. i have a galaxy s mine are under settings tethering etc, also have you got pc companion instaled wiyh correct drivers for pc?
Theres an app called Z4Root try that.
Itsca one click root app.
yep usb debugging try that also click installing of off market apps see if that helps.
Does the same usb work on the other phone? if so settings need to be changed. i have a galaxy s mine are under settings tethering etc, also have you got pc companion instaled wiyh correct drivers for pc?
Theres an app called Z4Root try that.
Itsca one click root app.