1. Make a backup of ur Internal Memory
2. Make a factory reset (Settings > Accounts > Back Up and Reset > Factory Data Reset > Reset Device > Delete All/Erase Everything.)
3. Conect it to Kies 3
4. Kies 3 will give u the info you need for know ur correct CSC. This will be btw parenthesis close CSC.
5. Knowing ur CSC, take a look for this firmware in Sammobile.com
6. Download and flash it with ODIN (Dont flash a "Black EDITION" if ur phone isnt it)
7. If this not work, you can get it to repair
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