Before you tinker with a phone, a full partition dump is essential. This tool lets you read the entire flash memory (ROM) and write it back. If you have a backup from a working phone, you can rebuild a dead one.
It offers a low-level format option that official tools avoid, including: st-mtk universal tool
Newer Dimensity processors (Dimensity 1000+) have hardened bootroms. The ST-MTK tool may not work on these without a paid authentication server (some versions require an NCK dongle or cloud credits). Before you tinker with a phone, a full