Things You'll Need
Instructions
Turn off the Sony PSP and remove the battery and memory stick from the device. Place these aside.
Insert the Magic memory stick followed by the Pandora battery. Your PSP will turn on and your PSP will now be in service mode.
Press the "O" button (or the "X" button depending on the version) twice to downgrade the PSP firmware back to the original PSP firmware 1.50. Press the "X" button to shutdown the PSP after the install completes. When the firmware is reflashed, all of the corrupted data is erased and replaced with fresh data.
Remove the battery and memory stick and reinsert the normal ones. Turn the PSP on and go to the "System Update" icon on the PSP menu. Select it and select "Update Via Internet." Your PSP will be updated to the most recent PSP firmware and the corrupted data is now fixed.