Tutorial written by Black_Skull, translated by KoubaK, vb_master redid banner with assistance from l337espeon.



Introduction
//After the release of the 2.71 downgrade by Dark_AleX. Now he comes and delight us with another, doing the same function, but simpler.
Now the 1.50 firmware dump becomes useless, simply, you take the EBOOT.PBP of the desire update (1.50-2.71), yes you can reinstall a clean
copy of 2.71 again, if any possible failure.

Precautions
//The Downgrade is a delicate process, since we are going to format the flash memory (flash0) of the PSP and reinstall a new firmware, so make sure you battery is fully charged, and the AC adapter is connected to the PSP.

//If your PSP has a TA-082 mobo, you can only downgrade to firmware 2.50.
DO NOT TRY TO DOWNGRADE TO A LOWER FIRMWARE.

// DOWNGRADE AT YOUR OWN RISK! Neither Black_Skull or Dark_Alex or any other person will take responsibility for any failure resulting in a brick.

Wondering if your PSP has a TA-082 motherboard?

//Simplest thing ever
Just Open the UMD Door and look if you see any numbers in the top right hand-side, look for this "IC1003". In the picture below you can actually see an example.
//If we see, in the opposite side, and under the chassis of the tray of the UMD, and with the label "IC-6001", you will be able to lower it to the firmware that you want
If not, only to 2.50.

Downloads

//2.71 Firmware Update: http://dl.qj.net/Firmware-2.71-PSP/p...8046/catid/163

//Dark_AleX's HEN C + Generic Downgrade- Packed by Black_Skull: http://vbmaster.portablesofdoom. or...lack_Skull.rar

Available Firmwares: http://dl.qj.net/PSP-Firmwares/catid/163
1.50, 1.51, 1.52, 2.00, 2.01, 2.50, 2.60, 2.70

How To Update To 2.71

*If you already have 2.71, just skip this step.
//Simply, just download the 2.71 FW EBOOT.PBP from the link above, and place it in PSP/GAME/UPDATE (create the UPDATE folder yourself).
Now, Go to Game > Memory Stick and start the update from there.
Follow the steps on the screen to update to 2.71.

//Remember to follow the steps directly, if not, say good-bye to your PSP.

Installing the files

//Download the "HENC 2.71 + Generic Downgrade- Packed by Black_Skull.rar" from above, un-rar and copy every file to the ROOT of your Memory Stick (where the MP_ROOT and PSP folders are).

-3 txt files (*.TXT)

-2 binary files (*.BIN)

-1 PRX (*.PRX)

-1 folder named PSP.

//Remember to overwrite the PSP and GAME folders.

//Now do not forget to do this, after downloading the firmware desired, take the "EBOOT.PBP" and rename it to "UPDATE.PBP". Then just copy the file in PSP/GAME/UPDATE folder.

Okay, Everything its done, for now, lets get this started.

Activate the Homebrew Enabler

//Connect the AC adapter to the PSP, highlight the "PHOTO" icon and press the "Triangle" then "Slideshow".

Few things could happen:

//OPTION A: The PSP freezes, just restart manually and try again.
//OPTION B: RED SCREEN. Do not scream, nothing has happened, the process just simply failed.
Just reset manually and try again. (This could happen several times...)
//OPTION C (the good one): BLUE or GREEN SCREEN: The process was a success; the PSP will automatically reset itself.


Downgrading to the desired firmware

//Make sure your battery greater than or equal to 75% charged (100% recommended), because if not, it will not start.
Go to GAME > Memory Stick and start the application.
//If your battery is less than 75%, the PSP will restart without displaying any errors (that is a bug which does not display errors). If everything goes well then it will display something like this "Doing preparations", then "Extracting special PRXs".
//After the screen will return to magenta text, and it will display if you accept the risks. By pressing "X" the process will start. It will display formatting flash, creating directories, writing IPL, and writing files and a percentage.
//When it finishes will say to press "X" again.
The PSP will restart itself and your desired firmware will be installed.

Now you can format the Memory Stick!