mobile

Im sure this has happened to other people as well but have yet to find and answer on fixing it. I was on the Lollipop update and was having some issues and decided to flash back to 4.4.2 to wait for the OTA. After flashing i have lost service did a factory reset and still got the same thing im currently stuck on wifi only. I have tried flashing different modems and got the same thing any ideas on what is causing this?