Unauthorized firmware downgrades in arcade machines can lead to security vulnerabilities, cheating, and hardware malfunctions. To prevent such issues, consider implementing the following effective measures:

1. Secure Boot Mechanisms: Use cryptographic signatures to verify firmware authenticity during startup, blocking unauthorized versions.

2. Firmware Encryption: Encrypt firmware files to make them unreadable without proper decryption keys.

3. Hardware-Based Locks: Integrate tamper-proof chips or secure elements that restrict firmware modifications.

4. Remote Monitoring & Updates: Deploy a system that allows only authenticated updates from a trusted server.

5. Physical Security: Secure arcade cabinets with locks or seals to deter physical tampering.

By combining these strategies, operators can significantly reduce the risk of unauthorized firmware downgrades and maintain the integrity of their arcade machines.