Theres a few ways on the amlogic chips to recover boxes, but theres also many ways to recover these units. I will talk about which I have used and others. In reality it is really difficult to fully brick one of these units permanently. I will start off with the basics and work my way up to the more advanced methods.
Everything in this document was sourced from somewhere online. If you want original links please ask me if I havent already posted them in one of the Image Source links. This document does NOT contain any proprietary knowledge that wasnt already sourced from the internet.