Ensure your PC can recognize the device in Download Mode.

Standard firmware (stock or custom) is signed with Samsung’s private key. The J730F U8 bootloader refuses to boot anything signed with a test key.

Have you successfully flashed the Top patch? Tell us your binary version in the comments below.

Generally, developers on XDA-Developers (like afaneh92 or corsicanu ) or established firmware aggregators provide these files.

: Click Start . Once the process is finished, your device will reboot with a fully patched and working network. Critical Safety Tips