Going Back to Stock Firmware From Custom Rom

[electronurd1]

Hi all,

Total beginner question... I have searched and searched and cannot find a way to revert my s4 mini back to the stock firmware from a custom rom. Every time I try to install the firmware via odin I just get secure check fail : aboot error.

I had installed a custom rom via TWRP and have tried everything to get the device back to a state to just install a samsung firmware?

Any help would be appreciated.

Thanks