Here is the guide you’ve all been waiting for,

Warning: Do not update your PSP via the network update as this will update your PSP to firmware 3.51, which is non-downgradable. You should also note that there is the slightest chance that you could Break/Brick your PSP and UberGaming are not responsible for anything that happens to your PSP. It is also highly recommended that you disable the ‘UMD auto start in your PSP’s system settings. Okay, firstly make sure you have everything you need, make sure you have all of the following;

• A Sony PSP with 3.50 (update instructions below for lower firmwares below.)
• A lumines UMD, either the EU (ULES00043) or US (ULUS10002) version. The original, Platinum, or Greatest Hits versions are all fine.
• The 3.50 downgrader package which can be found [Only Registered users can see links . Click Here To Register...].

1. If you already have a PSP with firmware 3.50, skip to step 3, otherwise carry on reading. Download the 3.50 firware EBOOT [Only Registered users can see links . Click Here To Register...]. Now connect your PSP to your computer/laptop and select ‘usb connection’ from the settings tab on your psp to switch on the usb connection. Now browse to your PSP’s memory stick on your computer by going to ‘my computer’ and the PSP should be there and it’ll be shown as ‘removable disk’ or something like that. double click on the icon and if there’s a PSP folder in there, you have the right device. Now go to where the 3.50 firmware EBOOT that you downloaded is and right-click and select copy and navigate to this folder: (The name of your PSP’s drive e.g. C: or F>PSP>GAME. Now create a new folder called UPDATE and paste the 3.50 EBOOT in there. (Make sure you name the eboot EBOOT.PBP) Now disconnect your psp from your computer.
2. Now turn your PSP on and go to the GAME tab and then press down on the D-Pad until you get to ‘Memory stick’, press X and you should see a file called ‘3.50 update‘ or something along those lines and press X, you will now be prompted to install the firmware, just press yes and wait until the firmware is installed. Now go and check what firmware you now have installed on your PSP by going to the settings tab on your PSP and going down to system settings then system information, if your firmware is anything else than 3.50 then something’s gone wrong and you’ll need to go to the support forum . Now DELETE the UPDATE folder you created with the 3.50 EBOOT in.
3. Now connect your PSP to your computer again and navigate to the ‘3.50 downgrader package’ which you downloaded (The folder should be called HEN350) and copy the GAME folder you have just downloaded to your ‘PSP‘ folder on your memory stick, now download the firmware 1.50 EBOOT [Only Registered users can see links . Click Here To Register...]. Rename the 1.50 EBOOT to UPDATE.PBP (This MUST be done!) and now copy it to the folder: PSP/GAME/UPDATE on your PSP.
4. Now disconnect your PSP from your computer and insert your Lumines UMD into your PSP and start the game up. The screen will clear to black and fill with a light blue color, then the PSP will return back to the tabs with settings etc like when you first turn your PSP on. If not, try again. Check that the downgrader is running by going to system settings, then to “System Information” and it should show up as system version 350 HEN. If it is showing up as 3.s0 HEN then go to the Game menu and run the ‘X.YZ update‘. Itis now recommended that you plug your AC adaptor into your PSP.
5. If you have an unpatched TA-082 or higher PSP motherboard, you will be prompted to allow the downgrader to patch your motherboard so it can be safely downgraded. The downgrader will not let you proceed without patching, if your motherboard requires it. Before the downgrader does anything to your PSP it will ask for you to agree to what it is doing, if you no longer want to continue press the R button. Once you have agreed to downgrade, do NOT turn the power off or remove the memory stick. Once the downgrade is complete, the application will ask you to press X and restart your system.
6. If your PSP says the settings are corrupt when you turn it back on, just press X (Or circle for JAP PSP’s) and you will have to enter the time etc again. Now you have an amazing 1.50 and you can run homebrew and ISO’s (UberGaming do not in any way promote the use of ISO’s unless you actually own the game.)
You’re finished! It is recommended that you now upgrade to firmware 3.40 oe-a, a guide to upgrading will be posted soon.
I hope you like the guide and if I receive sufficient praise/feedback, I will continue to write guides like this for people like you,
Thanks,

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This is great Sir Spiral ...
Very useful to me as noobie to PSP.
I'll study this procedure you posted before using it on my PSP ...

+rep added

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......... cabanerofr .........

Sorry for being a n00b, but is there a way to downgrade 3.50 PSP without original lumines UMD?

Can you downgrade a psp slim with 3.80 installed? I do have a copy of Lumines.

you should do 3.71 because im completely confused well i think i know how to but don't want to brick my psp if im wrong

excellent tutorial. Really thorugh and simple.

just a few questions though,

what are the risks? what could happen, even if following the exact instructions, that would cause the psp to "brick"?

Why do you reccomend then upgrading to 3.40oe -a or whatever it is?

Dont worry, i wont hold anything you say against you, just please be honest.

thanks alot

nooney666