Jerry wants to get his Samsung Note 4 mobile device repaired. It keeps booting. Leo says that mobile devices are now generally considered disposable. Leo says to try refreshing the phone. To do this, he should go to Settings > Backup and Reset > Restore to Factory Defaults. If that doesn't work, then he could try calling Samsung and ask if they would repair it. They'll really want him to buy a new phone, though.
Jerry can also try going to the XDA-Developers. He can look up the exact model of his phone and search for a custom ROM by rooting the phone. He will have to replace the boot loader, but it could be the solution he's looking for.
iFixIt has a Note IV repair site that can show him how to fix his phone with tips, parts, and tools.