With revision 4 active, your PSP can now execute the 5.00 M33 installer, which strips away the old partition limitations.
Many M33 users encounter an error stating their version is 9.90, preventing updates. This was a "spoof" meant to stop Sony from forcing official updates. Completely shut down the PSP.
Before proceeding, backup your PSP's memory stick and any important data to prevent loss during the upgrade process. psp 352 m33 upgrade to 660
Follow the on-screen instructions (usually pressing X to test, then X to install). Troubleshooting
: If you receive a "DRNFFFFFFCD" or "dadada" error, you likely have corrupted "keys." Use a tool like Chilly Willy's Key Cleaner to fix your IDStorage before trying the update again. PSP: Updating from the 3.xx OE CFWs to the 6.60 ME CFW 5 Sept 2013 — With revision 4 active, your PSP can now execute the 5
Ensure ISOs are in ms0:/ISO/ folder (uppercase "ISO") with proper filenames (no special characters). UMD ISO Mode should be set to "Sony NP9660" in VSH menu.
Congratulations! You have upgraded from 3.52 M33 to 6.60 PRO-C2. Your PSP can now play modern ISOs, use newer emulators, and take advantage of all modern plugins. Completely shut down the PSP
This is the safest way to leapfrog versions.
While the process is safe, performing any firmware flashing carries a slight risk of bricking if the console loses power. Phase 1: Preparing Your Memory Stick
: If a standard Pandora Battery doesn't work, your PSP is "hard-bricked." This is more serious and usually requires a hardware flasher or a professional repair service.