Your neogeo.zip might be missing the sfix.sfx or other specific region files. Download a "Full" Neo Geo BIOS to cover all bases. Conclusion
The Ultimate Guide to MAME 0.139u1: Finding and Installing the BIOS Pack mame 0139u1 bios pack hot
Once you have downloaded your BIOS pack (usually a collection of small .zip files), follow these steps to get your games running: Your neogeo
Because MAME 0.139u1 is an older "snapshot" from 2010, you cannot simply use a BIOS pack intended for the latest version of MAME. The file hashes and contents have changed over the years. The file hashes and contents have changed over the years
Ensure qsound.zip is in your ROMs folder.
Look for "Reference Sets." These are curated collections specifically verified to work with the 0.139u1 core without errors. How to Install the BIOS Pack