[Guide] Downgrade any Phat PSP

[MixedBag]

To downgrade/install custom firmware on your PSP Phat (any firmware) you need a pandora's battery and magic memory stick.

There are 3 ways to obtain these.


First Method
Must have access to another PSP with custom firmware already on or at 1.50. If you do not have access to a homebrew capable PSP go to the Second Method.

You will also need:
3.71 Official Sony Update. Download
1.50 Official Sony Update. Download
UPMS Installer. Download
And a memory stick with at least 256mb free.

Begin by extracting both of the updates to your desktop. Rename the updates to 371.pbp and 150.php. Make a copy of 150.php and rename it to UPDATE.pbp
You should now have 3 eboots, place them all on the root of your memory stick.
Extract the UPMS Installer.cso and put it in the ISO folder on the root of your memory stick. If it doesn't exist create it.

On your PSP scroll to the games folder on your memory stick and select the UPMS Installer.

You will then be presented by the main menu which has the following steps:
Step 1 - IPL Tools
Step 2 - Battery Tools
Step 3 - Firmware Tools
Step 4 - Utilities/Maintenance Options

Select step 1 and install Sleep Fix Multi-IPL to the memory stick.
Select step 2 to back up your battery eeprom automatically then select Create Pandora Battery (Service Mode).
Select step 3 and install UPMS without utilities. This is the fastest method.
Continue to step 4 to install 371-M33 updates including the 1.50 kernal.
Step 4 can also be used to install other firmwares such as 3.52

And that's it.
It comes with a manual to show you all the things that you can do with the memory stick.


Second Method
This method requires some soldering skills. If you have no soldering experience, I recommend you continue to the Third Method.

This method requires you to open your PSP battery up so it's recommended you have a second battery.
You will also need a knife/screwdriver and soldering equipement.

Step 1:
Use a knife or screwdriver to open your battery. Don't slid it in all the way as you run the risk of shorting it.



Step 2:
Remove the top of the battery.



Step 3:
Use a knife to remove or disconnect the leg of the chip, next to the word C04, IC104, or IC04. Again be careful as to not touch the other objects. The leg can be ironed back on if you want.




Step 4:
Plug the battery back into the PSP with no memory stick. The screen should remain blank but the power light will automatically come on. If it doesn't than you may have shorted the battery. To check this, charge the battery for a bit to determine if the battery needing charging or if it shorted.

Third Method
Look on ebay or similar and buy a premodded pandora's battery and memory stick.

Please do not reproduce this guide without my permission. It was written for pspspot.net and should not be posted elsewhere. Thank you.

[admin]

Its one hell of a guide right on the target

[Niko85]

nice thanks! i will be using this guide to downgrade my psp today if i get time. can i ask for help here if i need it mixedbag?

[JeDiKnIgHt]

great guide. i think i'll be checking ebay.

what firmwares are there downgraders for that dont need one of these batteries? i know 2.00 could be downgraded and 2.60, can 3.50?

[MixedBag]

Originally Posted by Niko85

nice thanks! i will be using this guide to downgrade my psp today if i get time. can i ask for help here if i need it mixedbag?

Yeah sure, feel free to ask for any help needed and I'll try my best to help .

Originally Posted by JeDiKnIgHt

great guide. i think i'll be checking ebay.

what firmwares are there downgraders for that dont need one of these batteries? i know 2.00 could be downgraded and 2.60, can 3.50?

3.50 can yeah as long as you have a UMD of Lumines (the first one) and is European, American, or Japanese it'll work. I can get a tutorial together if you'd like?

[Snocone]

I am loving these guides