mobile

Hello all, I have a samsung galaxy s4 model # i377m that was locked to bell. I purchased a unlock code for the phone and used a Kooko-(telus) sim card to enter the code. The code was successful however when I put my bell sim card back in the phone I can't send or receive phone calls properly. The dialer app opens and I can see my call history and browse my contacts but when I go to place a call the phone goes buggy, it will place the call but my screen goes black and I can't hear or be heard on the receiving end. It's really weird because everything else on the phone works, I have full reception and have the ability to send and receive txt and use data. The phone has a custom rom Cyanogenmod 12. I thought the rom had something to do with it so I downloaded and installed the stock firmware and I still had the same problem. At this point I have put cm12 back on the phone and must wait until someone can help me. I'm really lost for words.


Thanks for taking the time out of you're day to help me :)