You need to flash it back. I think, a method with using RKDevTool should help. Take a look at https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R5C#Option_3:_Install_OS_via_USB drive mad Maybe a firefly wiki will be helpful too: https://wiki.t-firefly.com/en/ROC-RK3328-CC/flash_emmc.html Thank yo...