So, I recently factory reset my J1 phone. It was twice. First bec. of the continuously switching on and off and then second, it was because I can't sign in with my existing g-mail account. I don't have any other solutions so last choice was to reset it twice. Now, I can't use and download apps. It got stuck on signing in with my existing account. It takes so much time. I even waited to sign itself in for the whole night but when I checkec it the next morning nothing happened. "The process com.google.process.gapps has stopped" and "Google Play Services has stopped" kept on popping out for like every 5 sec. I almost tried everything I saw on the net that can help me bug none of them actually helped with my prob. I just don't know what to do anymore. It sucks that I can't even use my phone. Please help me. I am hoping for your response. Thank you in advance.
The only solution left to you is flashing the phone with a stock firmware using Odin (on Windows) or Heimdall (on Mac).
Download the firmware from here(may need a registration)
Download Odin from here
Power down the phone, press volume down + home button + power button simultaneously
A menu should appear, press volume up button
Now connect the phone to the computer, you should see COM in blue (1), meaning the phone has been recognised.
If not, install drivers which can be downloaded from here - Download Kies and install it, will also install all drivers.
Click on AP (newer Odin version) or PDA (for lower Odin version) and browse to the extracted firmware folder. (2)
Click on Start and wait till the end (3)