How to DOWNGRADE your 2.0 PSP: Detailed Instructions
I post these in a separate thread mainly so that its not lost on page 17 of a huge thread and since so many people are still unsure of how the process works.
Again, these are just my instructions so I dont take any responsibility if you make any mistakes. And please read them all before asking any questions!!
And you dont need the frame_buffer.png file to run this downgrade - ignore that.
YOU MUST BE RUNNING VERSION 2.0 IN ORDER TO USE THE DOWNGRADER. UPDATE YOUR FIRMWARE TO THE LATEST VERSION BEFORE ATTEMPTING THIS
You will also need your PSP battery to be charged to 75% and be running off of the AC adapter (as per usual Sony firmware update requirements)
This downgrade has also been confirmed to work on PSP's from ALL regions (EU / US / JAP) and you can upgrade to 2.0 again should you want to. This has also been tested as working.
1. Start your PSP and activate a USB connection
2. From your PC, open up the PSP in your Windows Explorer and remove any copies of h.bin from the root folder of your PSP. (That is NOT in any directory on the memory stick)
3. Navigate to the PSP/PHOTO folder on your PC and delete any instances of pong.tif, overflow.tif, frame_buffer.png or any other file which you have used for any 2.0 exploits.
4. Extract the overflow.tif file from the MPHDowngrader.zip file and put it into your PSP/PHOTO folder on the memory stick.
5. Extract the h.bin and index.dat files from the MPHDowngrader.zip file and put these into the root of your memory stick. (Please note that this is x:\ [where x: is the drive letter your psp is assigned when using a USB connection] and NOT x:\PSP\ <- VERY IMPORTANT)
6. Extract the EBOOT.PBP file from the other MPH zip file and put that into a folder on your memory stick under PSP\GAME\UPDATE (you will need to create the UPDATE folder if it doesnt already exist)
So far we should have the following files on the memory stick
7. Press Circle on your PSP to exit USB mode and then navigate to the Photos section from the menu on the psp.
8. Press X to open up the photo's section and then the screen will turn black and some numbers and letters (hex addresses) will appear on the screen - this is normal so dont panic. You should see the memory stick flash for a few seconds as well.
9. Once all memory stick activity has finished, shut down your PSP by holding down the power. You may need to hold this for up to 15 seconds to shut off the PSP
10. Start up your PSP and activate USB mode
11. If you check the root folder on your PSP you should have a few new files and a file called index.dat.bak - If you do not have index.dat.bak - go back to step 1 and start again as you've done something wrong
12. If the file exists then press circle to exit USB mode and then navigate to the Game menu on the PSP and scroll down to Memory Stick. Press X and then you should see the PSP Firmware Update 1.5 listed in there. Press X again to launch it.
13. When the update appears follow the instructions on the update to start the process. You will see a percentage bar appear which will get to 99%
14. An error message WILL appear saying the update has failed and to contact Sony Support. This is normal so dont panic.
15. Power down the PSP by holding down the power switch for up to 15 seconds. Once the PSP has shut down, start it up again.
16. A message will appear on the screen claiming that the system settings have been corrupted. Press the circle button "O" in order to create new settings.
17. The PSP will reboot itself and start up again. You will need to enter your Time Zone and name again. Once you've done this, welcome to your happy new 1.5 PSP!
18. You can remove now any of the extra files that were installed as part of the downgrade now on the memory stick. (h.bin, overflow.tif, the EBOOT.PBP etc)