Hello All! This is my guide on how to downgrade to 6.20 and install cfw (Custom Firmware) on your PSP 1000,2000,3000 or go. This works on
6.35,6.38,6.39 BUT NOT 6.37!
You will need:
6.20 update http://dl.qj.net/psp/firmwares/psp-firmware-620-update.html
PSP downgrader http://dl.qj.net/psp/homebrew-applications/639-downgrader-v31.html
6.20 CFW http://dl.qj.net/psp/homebrew-applications/cfw-620-pro-b8.html
Step 1: First Things First
Unzip to desktop. Now take the 6.39 Downgrader and put it into PSP/GAME and Put the 6.20 update EBOOT into PSP/GAME/UPDATE.
Also it says 6.39 but it still works on the others. Now place the PRO UPDATE (CFW) into PSP/GAME also. But if you want permanent psp cfw then put the permanent one into PSP/Game too.
Step 2: Starting the Downgrader
Now unplug your psp and load the downgrader and After you downgrade to 6.20, you will get a BSOD (saying that your system information is corrupted), this is OK, just click circle to reset your system information and you will be back to normal.
Step 3: CFW
Now that you have 6.20 now load the pro update. Also if you want permanent then AFTER you load the pro update load the permanent update.