If you download a ROM that fails checksum verification (even without hacking), running the plugin can often “repair” it by writing the correct value based on the actual data. This is not true data recovery, but it makes the ROM loadable.
If you are using or looking for this specific plugin, it generally includes functions for: joukey gm checksum plugin
: Unlike older plugins that require manual input for memory addresses, this plugin reads checksum address information directly from the file. If you download a ROM that fails checksum
If you are diving into the world of GM PCM tuning with Joukoy GM Checksum Plugin joukey gm checksum plugin