You can downgrade any PSP Firmware version using the Pandora Battery.
'Pandora' can update ANY Official or Custom Firmware version:
e.g Official 3.71, 2.81, 2.50, or custom firmwares 3.10 OE, 3.40 OE, etc.

If you have a Slim PSP or an Original PSP with Official Firmware 3.51 or higher
you will need to use 'Pandora Battery' to Install Custom Firmware,
There are no Downgraders for slim PSPs or firmware versions higher then 3.51.

Read the "Gathering information about your PSP" Section for more information about
what you need to do to downgrade and install custom firmware onto your PSP.

You will need winrar to extract the files you download from this topic.
You can download the winrar for free here:

/!\ Warning: /!\

Upgrading / Downgrading your PSPs firmware will write to the 'flash memory' of your PSP.
There is a very small risk of bricking your PSP when writing to flash memory.
All downgrades should be successful if you follow the instructions carefully and correctly.
Although you may be one of the unlucky few that the downgrade fails on.
By following this guide you understand the risks you are taking with your PSP.

Formatting your memory stick will erase 'everything' on it.
Please make a backup copy of any important files to your computer before you continue.
(Like the savegames in your \PSP\SAVEDATA\ folder and any video / music / pictures you may have.)

Note: After installing the required files to your memory stick, wait for about 1 minute before closing the
USB connection and disconnecting the USB cable, Sometimes windows will keep the data in memory
and will write that data to the memory stick even after the installation looks like has successfully finished.

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What is Custom Firmware??

Custom firmware replaces your PSPs official firmware but it is not a permanent upgrade.
You can easily uninstall the custom firmware and to back to official firmware if you
don't like or don't want to use custom firmware anymore.

Custom Firmware has all the features of the official sony firmware, but also adds the ability
to load homebrew PSP ISOs and PSX EBOOTs directly from the game menu in the XMB.
so you can still play your original UMD discs, Music and Videos using custom firmware.

Custom Firmware also has an option to use 'No-UMD Mode' so you can run your PSP ISOs without a UMD inserted.
The 'Sony NP9660' No-UMD mode has the highest compatibility rate and almost all ISO games work with it.

If you have any PSP ISOs in 'DAX' format, you need to convert them to ISO or CSO files using UMDGEN,
Custom Firmware doesn't support the DAX format.

Your PSPs UMD Drive should be empty while upgrading / downgrading your PSP.
(except when downgrading from 3.03 & 3.50 you will need a UMD inserted to start the downgrader)
It is recommended to remove the UMD Disc from your PSP before you do anything in this guide.

If you don't have a USB cable but you have a memory card reader, you can use that instead.
when you see 'connect your PSP to your computer and make a USB connection',
Turn off your PSP, take the memory stick out of your PSP and insert it into your memory card reader.
When you see 'close the USB connection and disconnect your PSP from your computer'
Take the memory stick out of your computer and insert it into your PSP and turn your PSP on.

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Contents of this topic:

Gathering information about your PSP:
Checking your PSP Firmware Version
Checking your PSP Motherboard Model
What should I do next?

Upgrading / Downgrading Firmware:
Updating your PSPs Firmware
Downgrade 2.00 to 1.50
Downgrade 2.71 to 1.50
Downgrade 2.80 to 1.50
Downgrade 3.03 to 1.50
The 3.03 downgrader requires you to use an 'unpatched copy' of Grand Theft Auto : Liberty City Stories UMD
to start the downgrader. The unpatched copy of the UMD has the 2.00 firmware update on it.

Downgrade 3.11 / 3.50 to 1.50
The 3.11 / 3.50 downgrader requires you to use a Lumines UMD to start the downgrader.

Installing M33 Custom Firmware:
5.00 M33 + Update 4 NEW!!
5.00 M33 1.50 Addon Files

Using the 'Custom Firmware' Recovery Mode
Configuring 'Custom Firmware'
Reinstall / Uninstall 'Custom Firmware'

Help with using 'Custom Firmware':

Mini Guides:
Installing PSP ISO games onto your PSP
Installing PSX EBOOT games onto your PSP
Installing Homebrew onto your PSP
Putting Music on your PSP
Putting Videos on your PSP
Putting Photos on your PSP
Customize your PSPs Background Picture
Joining Multi-part Rar Files
Converting Between ISO and CSO formats

Error messages you may get while running 'Custom Firmware'
The game could not be started. (80020321)
The game could not be started. (8002014C)
The game could not be started. (80020130)
This disc cannot be started. The region code is not correct.
Connection Error: The WLAN switch is not turned on.

How do I....
Stop the UMD from Auto-starting when I turn on my PSP?
Enable the flash player and WMA playback without wireless internet?
Switch the "Confirm" and "Cancel" buttons used in the XMB?

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Gathering information about your PSP

Checking your PSP Firmware Version

First you need to check what firmware version your PSP has:

To find your PSP firmware version:
1. In the XMB scroll to the left to 'Settings' (XMB is the main menu of your PSP)
2. Scroll down to 'System Settings' and press 'X'
3. Scroll down to 'System Information' and press 'X'
4. Your firmware version is what is written next to "System Software:"

If the System Software contains either 'SE' or 'OE' or 'M33' letters or your System Software is 1.50
(e.g 2.71 SE-C, 3.30 OE-A', 3.52 M33-3)
then you have custom firmware installed and can update to the latest version of
Custom Firmware by reading the "Installing Custom Firmware" section.

If your 'System Software' is higher then 1.50 then you will need to downgrade before you can install
'Custom Firmware', Follow the instructions in the second post on how to downgrade your PSP.

Checking your PSP Motherboard Model

This information is only needed if you need to use the 2.71 or 2.80 downgraders.
The Downgraders for 3.03 and higher can automatically detect your 'PSP Motherboard' version.

1. Open the UMD Door and face the screen away from you.
2. Look in the top right corner of the UMD Door.
3. If there is IC1003 written in gold on the top right then you have either a TA-082 or TA-086 PSP.
If there is no gold writing then you have a 'TA-079' PSP.

Here is a picture of a TA-082 PSP showing IC1003:

Code:
[Only registered and activated users can see links. ]
(Click the link above for a picture if you are unsure what you are looking for)

What should I do next?

If you have Firmware 3.51 or higher:
You will need to use the 'Pandora Battery' to install custom firmware onto your PSP.
You will need to find someone with a PSP that can run homebrew programs to convert the battery for you.
You can find the guide on making the Pandora Battery / Memory stick here ->

If you have Firmware 3.50:
Downgrade from 3.50 to 1.50
Install Custom Firmware

If you have Firmware 3.10, 3.11, 3.30 or 3.40
Update your Firmware to 3.11 or 3.50
Downgrade from 3.11 or 3.50 to 1.50
Install Custom Firmware

If you have Firmware 3.03:
Downgrade from 3.03 to 1.50
Install Custom Firmware

If you have Firmware 2.81, 2.82, 3.00, 3.01 or 3.02:
Update your Firmware to 3.03
Downgrade from 3.03 to 1.50
Install Custom Firmware

If you have Firmware 2.80:
Downgrade from 2.80 to 1.50
Install Custom Firmware

If you have Firmware 2.71:
Downgrade from 2.71 to 1.50
Install Custom Firmware

If you have Firmware 2.01, 2.50, 2.60 or 2.70:
Update your Firmware to 2.71
Downgrade from 2.71 to 1.50
Install Custom Firmware

If you have Firmware 1.51 or 1.52:
Update your Firmware to 2.00
Downgrade from 2.00 to 1.50
Install Custom Firmware

If you have Firmware 1.50:
Install Custom Firmware

If you have Firmware 1.00:
Update your Firmware to 1.50
Install Custom Firmware

Required Files:
Official Sony Update EBOOT for the firmware you want to upgrade to.

all firmware eboots here :

Now you have successfully upgraded your PSP firmware.

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Downgrade 2.00 to 1.50

Required Files:
Complete 2.00 to 1.50 Downgrader:
Download:
Code:
[Only registered and activated users can see links. ]
Mirror :
Code:
[Only registered and activated users can see links. ]
Note: Your virus scanner may give a 'false' alert about a PSP.Brick virus or trojan in one of the TIFF files.
Before the 2.00 downgrader was released there was a 'trojan' being spread that bricked PSPs when run.
It bricked the PSP by writing to the flash memory and erasing some important system files need to start the PSP.
The 2.00 downgrader 'writes' to the flash memory using a similar method so the anti-virus program thinks its the PSP Brick Trojan.
You can upgrade to Firmware 2.71 and use the 2.71 downgrader as an alternate way to downgrade if you want.

Downgrading Instructions:
1. Transfer any important data from your memory stick to your computer and then
format the memory stick using your PSP, its in the 'Settings -> System settings' menu.
Note: Formatting will erase all data from the memory stick.

2. Connect your PSP to your computer using a USB cable and make a USB Connection.

3. Right click the RAR file you downloaded earlier and choose 'Extract files...' from the menu and a new window will open.
If you don't have 'extract files...' on the menu then you don't have winrar installed. (Download link at the very top of this topic)

Select My Computer and then select the drive letter of your PSP and click "extract"
(My PSP memory stick drive letter is Removeable Disk (E but it might be a different letter on your computer)

Winrar will then unpack the files to your PSP Memory stick, this may take a minute or so.

Once its finished unpacking the files, Double click the 'Safely Remove Hardware' icon near the clock
Select the 'Sony PSP USB Device' and click 'stop', on the next window click 'Sony PSP USB Device' and click 'OK'
You should get the message 'This device can be safely removed from your computer', Click OK to this message.

4. Close the USB connection on your PSP (press 'O') and unplug the USB cable from your computer and your PSP.

5. Plug in AC adaptor and Open the 'Photo' Menu. This will launch the downgrader.
The downgrader will show some numbers and letters on the top of the screen, this means the downgrade worked.
Wait for one minute then turn off your PSP by holding the power button up for 4 seconds until it turns off.

6. Turn on your psp and go to the game menu and launch the 1.50 update boot.
7. Follow the instructions on updating to 1.50.
When the update reaches 99% it will show an error "The update failed... (ffffffff)"
This is normal, just hold the power switch up for 4 seconds until your PSP fully turns off.

8. Turn your PSP back on. You will get a corrupt settings error with a blue background.
Just press the "O" button and your PSP will restart with repaired settings.
your PSP should then go through the setup process again. (set date / time etc)

9. Check the "System Settings > System Information", you should have "Version 1.50"
10. Format your memory stick using your PSP after you've done the setup.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Downgrade 2.71 to 1.50

This downgrader will work on all PSP Motherboard versions.
You will need to have 75% or more battery power to do the downgrade.

This is the latest 'IdStorage Corruption Free' downgrader,
you won't need to repair your IdStorage after using the downgrader.

Required Files:
IdStorage Corruption-Free 2.71 to 1.50 Downgrader:

Required Files:
IdStorage Corruption-Free 2.71 to 1.50 Downgrader:

Mirror :
Code:
[Only registered and activated users can see links. ]
Downgrading Instructions:
1. Transfer any important data from your memory stick to your computer and then
format the memory stick using your PSP, its in the 'Settings -> System settings' menu.
Note: Formatting will erase all data from the memory stick.

2. Connect your PSP to your computer using a USB cable and make a USB Connection.

3. Right click the RAR file you downloaded earlier and choose 'Extract files...' from the menu and a new window will open.
If you don't have 'extract files...' on the menu then you don't have winrar installed. (Download link at the very top of this topic)

Select My Computer and then slect the drive letter of your PSP and click "extract"
(My PSP memory stick drive letter is Removeable Disk (E but it might be a different letter on your computer)

Winrar will then unpack the files to your PSP Memory stick, this may take a minute or so.

Once its finished unpacking the files, Double click the 'Safely Remove Hardware' icon near the clock
Select the 'Sony PSP USB Device' and click 'stop', on the next window click 'Sony PSP USB Device' and click 'OK'
You should get the message 'This device can be safely removed from your computer', Click OK to this message.

4. Close the USB connection on your PSP (press 'O') and unplug the USB cable from your computer and your PSP.

5. Turn off your PSP by holding the power button for 4 seconds then turn it back on.
(This will give your PSP a 'clean boot' so 'HEN' will have a better chance of loading in step 6.)

6. In the XMB of your PSP go to the Photo menu then open the HEND folder.

Note: It may take a few tries to get HEND to load, the TIFF exploit doesn't load all the time.
If you have a 'custom wallpaper', try setting one as it may increase the chances of HEND loading.
See the 'Customize your PSPs Background Picture section for instructions on setting a custom wallpaper.
If your PSP freezes, restart your PSP and try loading HEND again.

If HEND successfully loaded, you will see a blue screen and then either:
Red: The files couldn't be written to the flash, you will need to keep trying as it doesn't work all the time...
Green: The files were written successfully, The PSP will restart and you can go to the next step.

If you want to check if HEND is loaded, check your 'system firmware version', it should read 2.71-HEND if HEND is loaded.

7. Run the 'TA-082_86_Enabler' from the game > memory stick menu if you have a TA-082 /TA-086 PSP.
The program will detect if your PSP is a TA-082 or TA-086 and will patch it to run 1.50 if its needed.
If you are sure that your PSP is definitely a TA-079 then you won't need to run this and can skip to the next step.
If you are unsure, check the top of the post, under the 'Checking your PSP Motherboard Model' section

Note: If you have a TA-082 or TA-086 and don't run the 'Enabler' then you will brick your PSP when downgrading in step 8.

8. Run the 'PSP Update ver X.YZ' from 'Game' > 'Memory Stick' to start the downgrader.
9. The rest of the steps are pretty simple, follow the on-screen instructions.

10. When you turn your PSP back on you will get a corrupt settings error with a blue background.
Just press the "O" button and your PSP will restart with repaired settings.
your PSP should then go through the setup process again. (set date / time etc)

If the psp screen stays black when you turn on your PSP,
Try pressing the 'screen brightness' button near the start / select buttons.
For some unknown reason the screen might get put in the 'off' position after the downgrade on some PSPs.
I'm not sure why that happens, but pressing the 'screen brightness' button seems to fix it.

11. Format your memory stick using your PSP after you've done the setup.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Downgrade 2.80 to 1.50

This downgrader will work on all PSP Motherboard versions.
You will need to have 75% or more battery power to do the downgrade.

This is the latest 'IdStorage Corruption Free' downgrader,
you won't need to repair your IdStorage after using the downgrader.

Required Files:
IdStorage Corruption-Free 2.80 to 1.50 Downgrader:

Mirror :
Code:
[Only registered and activated users can see links. ]
Downgrading Instructions:
1. Transfer any important data from your memory stick to your computer and then
format the memory stick using your PSP, its in the 'Settings -> System settings' menu.
Note: Formatting will erase all data from the memory stick.

2. Connect your PSP to your computer using a USB cable and make a USB Connection.

3. Right click the RAR file you downloaded earlier and choose 'Extract files...' from the menu and a new window will open.
If you don't have 'extract files...' on the menu then you don't have winrar installed. (Download link at the very top of this topic)

Select My Computer and then slect the drive letter of your PSP and click "extract"
(My PSP memory stick drive letter is Removeable Disk (E but it might be a different letter on your computer)

Winrar will then unpack the files to your PSP Memory stick, this may take a minute or so.

Once its finished unpacking the files, Double click the 'Safely Remove Hardware' icon near the clock
Select the 'Sony PSP USB Device' and click 'stop', on the next window click 'Sony PSP USB Device' and click 'OK'
You should get the message 'This device can be safely removed from your computer', Click OK to this message.

4. Close the USB connection on your PSP (press 'O') and unplug the USB cable from your computer and your PSP.

5. Turn off your PSP by holding the power button for 4 seconds then turn it back on.
(This will give your PSP a 'clean boot' so 'HEN' will have a better chance of loading in step 6.)

6. In the XMB of your PSP go to the Photo menu then open the HEN_280 folder.

note: It may take a few tries to get HEN_280 to load, the TIFF exploit doesn't load all the time.
If you have a 'custom wallpaper', try setting one as it may increase the chances of HEN_280 loading.
See the 'Customize your PSPs Background Picture section for instructions on setting a custom wallpaper.
If your PSP freezes, restart your PSP and try loading HEN_280 again.

If HEN_280 successfully loaded, you will see a blue screen and then either:
Red: The files couldn't be written to the flash, you will need to keep trying as it doesn't work all the time...
Green: The files were written successfully, The PSP will restart and you can go to the next step.

Once the files have been installed, You can now continue to the next step.

7. Run the 'TA-082_86_Enabler' from the game > memory stick menu if you have a TA-082 / TA-086 PSP.
The program will detect if your PSP is a TA-082 or TA-086 and will patch it to run 1.50 if its needed.
If you are sure that your PSP is definitely a TA-079 then you won't need to run this and can skip to the next step.
If you are unsure, check the top of the post, under the 'Checking your PSP Motherboard Model' section

If you don't run this and have a TA-082 or TA-086 then you will brick your PSP when downgrading in step 8.

8. Run the 'PSP Update ver X.YZ' from 'Game' > 'Memory Stick' to start the downgrader.
9. The rest of the steps are pretty simple, follow the on-screen instructions.

10. When you turn your PSP back on you will get a corrupt settings error with a blue background.
Just press the "O" button and your PSP will restart with repaired settings.
your PSP should then go through the setup process again. (set date / time etc)

If the psp screen stays black when you turn on your PSP,
Try pressing the 'screen brightness' button near the start / select buttons.
For some unknown reason the screen might get put in the 'off' position after the downgrade on some PSPs.
I'm not sure why that happens, but pressing the 'screen brightness' button seems to fix it.

11. Format your memory stick using your PSP after you've done the setup.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Downgrade 3.03 to 1.50

This downgrader only works on 3.03 firmware so you need to have 3.03 firmware before downgrading
All PSP motherboards can be downgraded. This includes TA-079, TA-082 and TA-086 PSPs.
The downgrader will auto-detect and patch your PSP if it is needed before the downgrade begins.
You will need to have 75% or more battery power to do the downgrade.

You need to use an unpatched UMD copy of "Grand Theft Auto - Liberty City Stories" to do the downgrade.
This downgrader only works with an Unpatched "Grand Theft Auto: Liberty City Stories" UMD.
Unpatched UMDs will have the Firmware 2.00 update on it, UMDs with the 2.60 firmware update will not work.

Can't find an 'Unpatched GTA:LCS' UMD?, Check this thread to see if someone in your local area has a copy you can borrow.

Pictures of unpatched Europe UMD with the game serial highlighted and circled in red:
Europe:
Code:
[Only registered and activated users can see links. ]
Unpatched version game serials:, note: Patched versions will have '#2' at the end of the serial number)
U.S.A - ULUS-10041#, Europe - ULES-00151#, Germany - ULES-00182#

Required Files:
IdStorage Corruption-Free 3.03 to 1.50 Downgrader:
Download :
Code:
[Only registered and activated users can see links. ]
Mirror :
Code:
[Only registered and activated users can see links. ]
Downgrading Instructions:
Before you start, you need to make sure that 'UMD Auto-Start' is turned "off" in the 'Settings' -> 'System Settings' menu.

1. Transfer any important data from your memory stick to your computer and then
format the memory stick using your PSP, its in the 'Settings -> System settings' menu.
Note: Formatting will erase all data from the memory stick.

2. Connect your PSP to your computer using a USB cable and make a USB Connection.

3. Right click the RAR file you downloaded earlier and choose 'Extract files...' from the menu and a new window will open.
If you don't have 'extract files...' on the menu then you don't have winrar installed. (Download link at the very top of this topic)

Select My Computer and then slect the drive letter of your PSP and click "extract"
(My PSP memory stick drive letter is Removeable Disk (E but it might be a different letter on your computer)

Winrar will then unpack the files to your PSP Memory stick, this may take a minute or so.

Once its finished unpacking the files, Double click the 'Safely Remove Hardware' icon near the clock
Select the 'Sony PSP USB Device' and click 'stop', on the next window click 'Sony PSP USB Device' and click 'OK'
You should get the message 'This device can be safely removed from your computer', Click OK to this message.

4. Close the USB connection on your PSP (press 'O') and unplug the USB cable from your computer and your PSP.
you can also plug in the AC Adaptor into your PSP so you have a 'backup' power source.

5. Insert the unpatched copy of "Grand Theft Auto : Liberty City Stories" into your PSP

6. Go to the game menu and start the UMD Game.

7. When the game gets to the 'loading savegame' then the screen will clear to black and fill with a light blue colour.
After this the PSP will reset itself, once you are back in the XMB remove the UMD.

If this does not happen make sure that you have the unpatched verson "Grand Theft Auto : Liberty City Stories"
It should have a 2.00 firmware update on the UMD. If it does not then it is a later version and can not be used to downgrade.

If your PSP turns itself off / freezes, Turn off your PSP by holding the power button for 4 seconds.
turn on your WLAN switch (the switch on the left of your PSP should be 'up'), turn your PSP back on and run the game again.

8. Check that HEN is running by going to "Settings -> System Settings -> System Information"
If your System Version is '3.03 HEN' then HEN is loaded, proceed to step 9.

9. On your PSP, go to the Game -> Memory stick menu and run the "Update X.YZ" program.
10. If you have an unpatched TA-082 or higher motherboard you will be prompted to patch your PSP so it can be safely downgraded.
The downgrader will not let you proceed without patching, if your motherboard requires it.,

11. Before the downgrader starts, you need to agree with what it is going to do.
If you no longer want to downgrade, press the "R" (Right Shoulder) button.
If you agree to start the downgrade press the "X" button.
Warning: Do not unplug the PSP or try and restart it yourself, doing so will brick your PSP.

12. When the downgrade has finished the PSP, you will need to press X to restart your PSP.
13. If you get a blue screen error saying the settings are corrupt then press O to restore the default settings.
(You will need to re-enter all the settings into your PSP again, like time / date / network settings etc...)

14. Format your memory stick and then you are all done. You should have a Firmware 1.50 PSP. ;D

Note: If your screen goes black after the 'corrupted settings' part but you hear the boot-sound,
Try pressing the 'screen back-light' button thats located near the start / select buttons.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Downgrade 3.11 / 3.50 to 1.50

These downgraders work on 3.11 and 3.50 firmware, make sure you download the correct downgrader for your PSP.

If you have previously downgraded your TA082 PSP using a downgrader you may not be able to install official firmware.
If you get a 'System Configuration is not correct' error then you will need to update to Firmware 3.11 and use the 3.11 Downgrader.

All PSP motherboards can be downgraded. This includes TA-079, TA-082 and TA-086 PSPs.
The downgrader will auto-detect and patch your PSP if it is needed before the downgrade begins.
You will need to have 75% or more battery power to do the downgrade.

You need to have an Original, Platinum or Greatest Hits version of the "Lumines" UMD to do the downgrade.
Can't find a copy of the Lumines UMD? Check this thread to see if someone in your local area has a copy you can borrow...

USA Versions:
'Original' -> ULUS-10002. Working... (UMD does not have a firmware update)
'Greatest Hits' ->ULUS-10002GH. Working...

Europe Versions:
'Original' -> ULES-00043. Working... (UMD has the 1.50 firmware update)
'Platinum' -> ULES-00043P. Working...

Japanese Versions:
'Original' -> ULJS-00005. Working...
'The Best' -> ULJS-19005. Not working if the UMD has a 3.51 firmware update.

Korean:
'Original' -> ULKS-46005. Working...

You can find the code written on the spine of the box near the bottom in small writing.

Here are some pictures of the USA and Europes version 'Game Box' and 'UMD Disc':
USA Version: Game Box, Game UMD
Europe Version: Game Box, Game UMD