Problem with registering on network

Jan 29, 2014
Hello all,
I have a strange problem, will be glad if someone could help.
After replacing the LCD screen successfully (the touch works good and the display as well),
the phone won't register automatically on the network. The SIM is recognized by the phone.
When trying to register manually, the phone finds all the networks but won't register on any of them.
Tried different SIMS, same result. Should mention that 3g preffered network type is selected.

Thank You.