Check here. http://samsung-updates.com/device/?id=GT-P5100 If the Firmware is on there, you can use a tool like Odin to flash the firmware to the device. http://odindownload.com/ You will need to install the Samsung USB drivers first. There are a few guides to using Odin around. This guide is for the Tab 4 but should also be applicable to your tablet. http://forum.xda-developers.com/tab-4/general/guide-how-to-restore-stock-firmware-t2979006