Hi! You could download the latest firmware and flash it to your tab via Odin, Or if you want to install a custom ROM , you can download the zip file that contains the custom ROM, Put it in your SD card, And flash via twrp.
Hi! Did you try flashing your phone with the repair firmware? Note: Some user had the same problem he said that he got it fixed when he flashed the MODEM file (through Odin of course).