after doing some more test, i've noticed that it has nothing to do with usb whatsoever - the problem still is that i am unable to find my service provider when searching networks. at first, i thought it might be problems with my sim card, but today i've bought a new one, and the problem still persists. sometimes the network connects automatically, but disappears a few minutes later. the phone isn't carrier locked, but i tried it with a different sim from a diffirent carrier and the network was up and running in a few seconds after the phone was turned - unlike my main sim card, which gives me the good old "No service"
