How To Downgrade PSP from FW above 3.5

Tools: Pandora battery and Magic Gate Memory Stick

Making a MMS without a CFW PSP

Eboot files needed: 1.50 and 3.80

Software needed: Rain’s Simple MMS Maker



To use the program: 1. select DCv4 from the dropdown list and locate the 3.80 eboot file. 2. Load the 1.5 eboot file. 3. check Format Memory Stick. 4. check 1.50 Kernel addon if you have a fat PSP. 5. press the big button Make MMS.

Downgrade the PSP

1. Take out the original battery
2. Insert the memory stick
3. Insert the pandora battery
4. Press L on PSP and hold while powering on the PSP, a black and white menu should pop-up. Follow on-screen instructions.

5. When done, turn off PSP and replace the pandora batter with original battery

Video tutorial available here.

Source

Error: “The game could not be started. (80020321)”

To play any ISO games, you need to have an UMD game disk in your PSP. It does not matter what game it is.

Another way is to use the No-UMD mode that is configurable in the recovery menu, but it is not compatible with all games. To get into this menu, shut off your PSP, press & hold R while turning PSP back on. When the recovery menu loads up, go down to Configuration section and select the “UMD Mode” option -> press the X button until you see “currently: M33 driver -NO UMD-”. Exit Recovery screen. This will restart your PSP.

Source