Originally posted by PeaInAPod:

---

@TMNTPOWER

Heres a guide to take a ver. 2.71 PSP with your motherboard to firmware 1.5

To begin with put aside all the files you already have for the downgrade in a separate folder and format your memory stick. I say this to ensure two things 1)that you don't get the files I give you and the ones you already have mixed up, and 2) formatting the memorystick before a downgrade decreases your chance of bricking.

Okay to begin you will need the TA-082 2.71 Downgrade Files and the firmware 1.5 update files. Download links below...

TA-082 2.71 Downgrade Files
Firmware 1.5 Update


Now to prepare to downgrade...

1)1. Open the 2.71 TA-82 downloaded files and extract all files to the root (topmost/first folder) of the memory stick. As shown below...



2)Copy over the 1.5 update EBOOT.PBP renamed to UPDATE.PBP into X:\PSP\GAME\UPDATE\ Were X is the drive letter for your memory stick.

3)Now either terminate the USB connection or remove the memory card and insert it abck into your PSP. Start your PSP and run HEN D by going to the photo menu and entering the HEN D folder.

Note: For the next few steps make sure your battery is charged to at least 75% and your charger plugged in.

4)Go to the GAME menu and and run 1.50 enabler.

Read: The 1.5 enabler will tell you if you can run 1.5 or not. If it says you cannot press X to alter keys, don't continue till it says your settings will run 1.5

5)When the program exits back to the XMB run UPDATE X.YZ.

6)When your PSP has finished downgrading press X to restart your PSP.

7)When you turn your PSP on there will be a blue screen with a bunch of words and letters and what not. It will say to press O, so Press O.

8)Congradulations your now at firmware 1.5!


This excellent guide taken from...
http://forums.qj.net/f-psp-hacks-9/t-gui...uide-90916.html


Also once downgraded to firmware 1.5 I presume you wish to upgrade to a custom firmware like 3.03 OE-C for example. So to help you out I have included links to download installers that make the install process for firmware 3.03 OE-C, 3.40 OE-A, and 1.5 Recovery mode easy as pie.

3.03 OE-C Easy Installer

3.40 OE-A Easy Installer

Firmware 1.5 Recovery Mode Easy Installer (you want this trust me)

---