Downgrading a 2.71 is the Safest
and the Easiest
way to downgrade. This method is called Generic Downgrader. It is safer than any other downgrader because it formats the Flash0 and Downgrades in a similar performance the way Sony Updates work.
The Generic Downgrader allows you do downgrade from 2.71 to ANY FIRMWARE. This part of the guide was not meant for TA-082 use. Please check up next time.
Time to downgrade a 2.71 PSP
First off upgrade to firmware 2.71 if it is not already 2.71. Now Install\Start HEND if it is not already started\installed.
1 - DO NOT FOLLOW this part of the guide if your psp is a ta-082 go to 2 if your psp is a ta-082. To check, open your UMD door and you should see the number IC1003. That means your psp is a TA-082/6
To downgrade a psp that is TA-079 - TA-081 upgrade your PSP to firmware 2.71. This is the link
After upgrading run HEND. It is a Homebrew Enabler Revision D created by Dark_Alex, an amazing developer. This is the link to HEND
To install HEN-D you must first place all the files into your memory stick and then go to the Photo menu and hit the START button at the HEN-D selection. You should see a blue flash and then a green flash if everything went well. If you see a red flash DO NOT PANIC. Do the process again.
After HEN-D is installed completely cold boot your psp. To do this you must hold your power switch for ten seconds and your psp should totally shut down. Then hold it up again and you should see the Sony Computer Entertainment sign.
Now restart HEN-D, to do this just go to the photo menu like before and hit the START button.
Download the Generic Downgrader by Dark_Alex. Here is the Link
Open up "updateflasher.zip" and you should see a folder called updateflasher. open it. Go into MS_ROOT then into PSP into GAME and you should see a folder called UPDATE. Copy this to the game folder of your psp. So in the zip folder you should carry this file
<- copy the update folder.
Now you want the 1.5 update. Download this file, link is here.
Name the 1.5 update file "UPDATE.PBP" (without the quotes) and place it into the UPDATE folder you just copied to your psp.
Now for the heart beating scary bit. Actually downgrading to 1.5.
Step 1 - Check all your work. Read and ReRead the tutorial above and the readmes if you'd like. So basically check all your files, where you placed them, and make sure all of the files are there.
Step 2 - Run HEN-D if it is not already running. Push start to start it. you should see a Blue flash and the psp will restart.
Step 3 - Say "I agree to what i am doing to my psp, and only I am responsible for what i do to it. No one else."
Step 4 - Go into the game menu. There you should see a program called "Update X.YZ" run it. If you agree push [X] and all should start
Step 5 - DO NOT TOUCH your PSP. Let it sit until it says 100% complete.
Step 5 - (Optional) If the screen darkens a little push the directional pad ONCE! I did this so that it would no go into sleep mode.
Step 6 - Reboot the psp.
Step 7 - Once again say "I agree to what i am doing to my psp, and only I am responsible for what i do to it. No one else."
Step 8 - Welcome to 1.5 Homebrew land! :D
Step 8 (optional) if things did not go according to plan. I do not want to state what happens to your psp.
Step 9 - Post your results.
Again - All actions are your own, NO ONE elses. Only yours.