mobile

Hi everybody, Yesterday my friend and i were trying to upgrade his Samsung Galaxy Core (GT-I8260L) from official stock jellybean 4.1.2 to kitkat 4.4.4 unnoficial. We rooted it succesfully, installed Super SU, and BusyBox. Then we downloaded a TWRP file to flash it through ODIN. the flash was succesfull but when the phone rebooted it got stuck at the download mode. It doesnt boot, and we can't acces the recovery by any means. it just turns the screen on and show the download mode screen (picture attached).

We have tried everything, but the thing is that the device isn't recogogniced by the pc (We've tried in a win 8.1 and win 7 pc, but had no luck.). It fails to install the right drivers. we've tried to download almost every samsung phone drivers, but none of them worked. ODIN also fails to recognize it.

we also tried Heimdall, but when we try to install the drivers it does recognize the phone as 'MSM7x27' for some reason.
We also have problems setting up the 'SAMSUNG Mobile USB CDC Composite Device Driver', failing to make it work every time we tried to configure it (Automatic Windows Driver Install or Downloading it manually).

I hope someone can at least guide us through the solution or suggest a way to fix it.

Thanks in advance

Attached Thumbnails