Next time we’ll talk about a way to downgrade and unbrick each and every PSP (you need another PSP for it, though).
Check Memory Stickâ„¢ and open ‘PSPâ„¢ Update ver 3.50’.
In this case, a tiff file is used to change the version number to 1.00, after which you’ll be able to update to 1.50. PBP file in X: PSPGAMEUPDATE (where X: is your PSP) and extract the MPH Downgrader zip in your PSP root (main folder). Don’t be afraid, this is just the program doing its work. If it fails to do so, just select the PSP root (main folder) manually. Unzip the Patch SFO EBOOT to X: PSPGAMEPatch SFO and the FW 1.50 EBOOT.
If you are prompted about replacing any files, click ‘Yes to All’. Wait about 30 seconds and restart your PSP (hold your power switch up until it switches off and turn it back on). You’ll then encounter another error, press O to restart. PBP file to X: PSPGAMEUPDATE (where X: is your PSP).
If your PSP crashes, do a hard reboot and try again. Sony didn’t like this though, so they made sure this wasn’t possible with all next releases and/or firmwares.
At one moment, you’ll get an error message as shown below. You’ll also be able to view the files contained within the folder now. Go to Game - Memory Stickâ„¢ and open the installer (1.50DDfor TA-079~081FW2.80PSP). I only suggest this method if you actually own this game, don’t go running to the store to get a copy.
Instead of using Liberty City (more details above), they used a save-game exploit and a copy of the nifty puzzle game Lumines to get in.Note that the installation is also very similar to the GTA version.(use google if the below links are offline) Format Memory Stickâ„¢ and confirm twice.Un RAR the downgrader and move all the files from the MS_ROOT folder in the root (main folder) of your PSP.If you have a higher firmware, don’t despair, as we’ll be discussing them in part two (a little more complicated though).As there’s a lot of different variables and different ways to work with them, we’ll be sending you up and down through this guide to the steps that matter for you.There are a lot of different ways to downgrade your PSP, which one you’ll have to use depends on your current firmware.