So.. since there is no way that you can downgrade a PSP unless you use a Pandora Battery, here’s how to do it without one:

I currently have PSP Official Firmware 4.05 this may work with other Official Firmwares but has not been tested, if this works for you on another firmware please let me know!

I am going to tell you how to get your firmware down to firmware 4.01 M33-2 without a Pandora Battery.

First you will need to download PSP Pandora Deluxe make sure it is at least newer than v.04! Then download PSP Official Firmware 1.50 not Custom Firmware or it will not work, and PSP Official Firmware 4.01 again not Custom Firmware or it will not work!

You can find all these files through Google or you can download them from here either in the Downloads section or via the links at the end of this post.

You can also view any images associated with this at the end of the post!

When you have them downloaded then extract them where you would like, I recommend your desktop.

Plug your PSP into your computer and copy everything off your memory card and save it to a folder on your computer, I recommend your desktop and naming the folder “PSP Backup”.

Then open up PSP Pandora Deluxe.

It will start on the Firmware + Pandora Options tab
When it comes up you should see were it says load PSP firmware files, click on “Load 1.50 Firmware” when you do that a box should pop up go to your desktop or to where you extracted the files and load the EBOOT.PBP for the 1.50 firmware, once done do the same for 4.01 once you have loaded the files you will see that the “Copy Firmware” check box is now clickable check off both firmware boxes.

Leave the Pandora Button Configuration alone as we will discuss it later and at this point should not be adjustable.

On the top tabs click on Installation Options
When you do that the Install Options are now available to you, click on the “Noobz 1.50 Downgrader” and the “Despertar Cementerio v7 (4.01M33-2)”. Under the “Other Options” section make sure to check the box that says “Copy the M33 1.50 Addon Installers”.

Ignore the Support Tools Options and Config/Status tabs for now.

Go back to the Firmware + Pandora Options tab
When you click on the tab the Pandora Button Configuration is now adjustable, leave it alone. You may change the buttons if you wish the main one in concern here is the Despertar Cementerio v7 option, please note for the last of this tutorial I have left the button configuration alone if you change it remember what you changed it to!

Under “PSP Information” at the bottom of the program make sure your PSP Drive Location is correct! If your PSP was connected when you started Pandora it should have automatically detected it, if is is not set right please change it now before continuing! Make sure you also have “1.50 FW” selected under the drive letter not “M33 FW”!

Under “Memory Card Options” make sure all three settings are checked off, please note if you are running an older version of Pandora they may not all be available to you: “Format + Prepare Memory Stick”, “Use MSPFormat” and “Inject IPL”

You can also Backup or Restore your Memory Card from here as well.

All you have to do now is push Start it will take a few minutes and it might look like it is not working but it is, it may ask you to do some things with your PSP so it is best to stay close by. Once done you may close Pandora as it is no longer needed.

Unhook your PSP and turn off the power.
Then take your PSP make sure you are holding down Right on your D-Pad and turn the PSP on, do not let go of the Right arrow until a screen pops up saying:
“Install 4.01 M33-2, Install 4.01 OFW and some others.”
Make sure it is on the 4.01 M33-2 and push X

It should then install and now you have PSP Custom Firmware 4.01 M33-2!

If you need any additional help please feel free to let me know and I will do what I can.
If you would like to know more about anything read the “readme” that comes with PSP Pandora Deluxe.

Downloads:
PSP Official Firmware 1.50
PSP Official Firmware 4.01
PSP Pandora Deluxe v3.1

Pictures:
PSP Pandora Deluxe v3.1

**I will update this later with some more images, if you need anything before then please feel free to contact me.