(Optional) If you have a PSP 1000 or early 2000, run the to make the firmware permanent. For newer models, use FastRecovery if the console restarts.

: Your PSP battery must be charged to at least 78%. Many updates will hard-block execution if the battery is low.

: On the PSP, go to Game > Memory Stick and launch PRO Update .

The process requires stepping through intermediate versions to ensure the system's internal updater can handle the leap. 3.52 M33 to 3.52 M33-4

This comprehensive guide covers everything you need to safely bridge the gap between Team M33’s legendary custom firmware from the late 2000s and the modern, highly compatible 6.60 ecosystem. Why You Must Upgrade 3.52 M33

Press to confirm. This ensures your PSP boots directly into custom firmware every time you turn it on.

Check your System Information to ensure it reads . Phase 4: Navigating to Official Firmware 6.60

Enjoy perfect compatibility with official PlayStation 1 classics conversions.

: Keep your PSP plugged into its wall charger during the entire update process.