A clean Super Mario Bros. 3 (USA).nes should have the SHA-1 hash: 9cd8b171... (check No-Intro dat files for accuracy).
Over time, ROM packs can become outdated, corrupted, or incomplete. Repacking or seeking a better version can provide: nes top 100 rom pack repack best
: This project provides a curated "best of" list for retro games. The NES set is approximately 21.9 MB and is optimized for use with the RetroArch - Nestopia Reddit /r/Roms: "Top 100 Game Packs" A clean Super Mario Bros