UPDATE: Since this how-to was first written things have changed. Sony has released firmware 2.01 which makes this downgrade impossible. A PSP bricker trojan was released because of this antivirus software will classify both the good and bad downgrade files as harmful. You should do more research into the current state of the downgrade before attempting. As far as we know our firmware links are still good, we are not hosting them so we can not vouch for their safety.
C.K. Sample, III, TUAW / WIN Blogger and author of the forthcoming book, PSP Hacks, got his hands on the version 2.0 downgrader and wrote up a thorough how- to complete with pics for us. He even takes the extra steps to upgrade and downgrade yet again, just to make sure such a thing is possible.
As you can see, I have 2.0 running with the browser on my PSP. 
Step 1: Download the downgrader from either here, here or here. Then make sure you get a copy of the original 1.5 firmware upgrader. I found my copy here.
Step 2: Connect your PSP to your computer via USB. On your memory stick, create a folder called UPDATE inside /PSP/GAME/ and place the EBOOT.PBP file from the 1.50 update inside this UPDATE folder.
Step 3: Unzip MPHDowngrader.zip. Drop overflow.tif into your /PSP/PHOTO/ folder. Put both h.bin and index.dat in the root of your Memory Stick.
Step 4: Disconnect your PSP from your computer and plug in the AC adapter.
Step 5: Navigate to Photo then Memory Stick via the PSP’s menu system and start scrolling down through your photos until you reach the overflow.tif picture.
You’ll know you’ve hit it when everything freezes and you get a black screen with a bunch of white text output.
If your PSP freezes without going to this black text screen, then hold the power button for about 10 seconds until the PSP shuts down, then hit the power button again to start it back up. Repeat this step until you get that black screen.
Step 6: Don’t panic. Hold the power button for about 10 seconds until the PSP powers off. Hit the power button again. Your PSP will start up, and if you navigate to your System Information, you’ll discover that your PSP thinks it is running version 1.0 of the firmware. It isn’t and you cannot run homebrew (yet).
Step 7: Navigate to Game–>Memory Stick, hit the X button, and navigate to the 1.5 updater. Make sure you have your PSP plugged in or the upgrade won’t work. Click the X button and update like you normally would. At the end of the upgrade you will receive an error saying that the upgrade failed and to contact Sony. Don’t panic. Ignore this and again force your PSP to power off and reboot.
Step 8: After the PSP reboots you will receive an error screen that is scary and confusing because it is in multiple languages. Don’t panic. Find the language you can understand and read the corresponding line. It notes that your preferences are fragged and that you need only hit the O button to restore some default-ish settings. Hit the O button. 
Step 9: The PSP will start back up and you will go through the initial setup like the day when you first bought your PSP. Do so and then go to the system info pane again, where you will see that you are rocking version 1.5. Run homebrew at will.
I ran through this entire procedure, then I downloaded the 2.0 update and installed that again, and then yet again went through the entire procedure again. It works like a charm. It’s a little time-consuming, but you can have the best of both worlds. Have fun!
I upgraded the firmware over wireless and it updated it to 2.01 not 2.0. When I select the overflow file it just says corrupted data?? no freeze or nuttin?
I upgraded the firmware over wireless and it updated it to 2.01 not 2.0. When I select the overflow file it just says corrupted data?? no freeze or nuttin?
Pete – if your upgrade worked correctly then you can delete all the files (especially the .tif file, else you’ll ‘crash’ your unit again.)
the .bin file, as far as i am aware, is the output of the code attached to the .tif file (after it does the buffer overflow.) the eboot.pbp is the update itself.
is the thing where u can remove the battery and keep the browser true? dus it work? wat is the % of it working? I really wanna downgrade to 1.50 but dnt wanna run the risk of bricking my psp and wasting
sony released the 2.01 firmware on their servers today. it’s not listed officialy, but when you do a network update now, it gives you 2.01 instead of 2.0. hate to say it fluke in posts 96, but you’re out of luck. the 2.01 firmware closes the exploit in 2.0 that allowed the downgrade to 1.5.
BEWARE UPDATING FROM SONY!!
BEWARE UPDATING FROM SONY!!
BEWARE UPDATING FROM SONY!!
BEWARE UPDATING FROM SONY!!
BEWARE UPDATING FROM SONY!!
if you have 1.51 or 1.52 firmware on your PSP, get the 2.0 firmware for http://pspupdates.qj.net in their files section or elsewhere. DO NOT GET FIRMWARE FROM SONY or a Network Update over wifi. you will be locked out of homebrew if you do.
ooooo… um.. Kinda sux being you, because the downgrader only works with v2.0. The whole purpose of sony releasing v2.1 is to stop people from downgrading.
Wow, must admit I was scared a little. Just one thing though, like someone mentioned about leaving a game in the unit, I had some saved game data on the memory card and it wouldnt work at first, so make sure you delete.
Also, does this not open up for multi region video playing on the UMD Disks??
Great Work Guys. This will sort it out till someone hacks the V.2.0 :-)
GUYS try this i finally got it to work, i had the same issues as most.. including the inability to c the black background with white text… do all the steps required and then make sure before u go to the photo option that your PSP UMD Drive is (((OPEN))) this worked for me and i hope it works for u.
Worked perfectly for me on a day old UK PSP. Now playing Streets of Rage and Gunstar Heros religiously :-D
I cant seem to be able to downgrade, when i go to the photo all that happens is that my psp frezzez but it turns OFF not black screen with letters. and it still sais 2.00 i need help down grading. my e-mail ios tigereye18056@hotmail.com some one please help
I read the article about the PSP downgrade. I have looked everywhere and read everything but come back to the same answers. My main problem with it is the overflow.tif file, once I open up the Photo section on my PSP (not the flash drive on my PC) the overflow.tif file says corrupt. I have tried using the frame_buffer.png file with it but that doesnt work. if you could help that would be great, thanks.
I read the article about the PSP downgrade. I have looked everywhere and read everything but come back to the same answers. My main problem with it is the overflow.tif file, once I open up the Photo section on my PSP (not the flash drive on my PC) the overflow.tif file says corrupt. I have tried using the frame_buffer.png file with it but that doesnt work. if you could help that would be great, thanks.
I read the article about the PSP downgrade. I have looked everywhere and read everything but come back to the same answers. My main problem with it is the overflow.tif file, once I open up the Photo section on my PSP the overflow.tif file says corrupt. I have tried using the frame_buffer.png file with it but that doesnt work. if you could help that would be great, thanks.
I just bought a PSP. How do I find out the firmware version? My PSP screen does not have Internet Browser symbol, can it still be v2.0?
Brian:
*re-download ALL the files.
*After that, extract (if zipped) ALL the files into a temporary folder.
*Then, re-copy ALL the files to the psp by right-clicking and selecting “copy” then “paste” for EACH file. Sometimes, dragging them causes problems.
*After copying, remove the PSP by selecting the “stop usb device” icon in the taskbar.
*note: be sure there are _no_ other pictures in the PSP folders. Be sure there is _no_ UMD in the slot. Be sure the PSP is plugged in during the _whole_ operation.
My memory stick does not have folders /psp/game or /psp/photo. Do I have to create these folder or these foders should already be in the memory stick by default?
HEy everyone
This whole downgrader thing is driving me nuts. All i want to do is play contra on my psp. My psp freezes up when i try to get into the tif file and ive tried powering off and all that. I’ve tried everything on this post list except the backgroud file on post 43 because i dont no were to download it . If someone could please let me no were i could get it i will gladly try that too. None the less if anyone has any other ideas or helpfull hints please feel free to email me at michael@damren.com. Thanks everyone and cheers to the people who have succeded i am extremlly jealous
Steps to use the MPH downgrader:
– Create an UPDATE folder in the /PSP/GAME/ folder of your memory stick
– Copy EBOOT.PBP (update 1.50) in /PSP/GAME/UPDATE folder
– Unpack MPHDowngrader.zip
– Copy overflow.tif in your /PSP/PHOTO/ folder of your memory stick
– Copy h.bin to root of your memory stick (meaning in ms0:/)
– Copy index.dat in root of your memory stick (meaning in ms0:/ as well)
– Plug the AC adaptor
You memory stick filesystem should look like this (where X is your memory sticks directory):
X:/h.bin
X:/index.dat
X:/PSP/PHOTO/overflow.tif (with no other pictures in there)
X:/PSP/GAME/UPDATE/EBOOT.PBP (the 1.50 Firmware update eboot)
What you do next is go into the Photo Menu on the PSP and it will show some jumbled text, which is normal. Wait about 30 seconds and then restart your PSP.
From there you will now have a new file in your PSP
Hey, I’ve just done this on my psp and it worked perfectly. I had a 1.52 version, now 1.50 and its great.
Thanks heaps.
Does this work on australian psp because i want to run homebrew and im not sure if australian psp is a japanese, american, or uk psp… but maybe i should get a japanese one
in the above instructions, the directories on the memory stick have to be in all caps. it won’t work otherwise.
Has anyone successfully used wab version changer as mine goes to work but doesnt load game.I am only new to psp but have version 1.00 firmware and trying to play original medievil game which requires version 1.52.
wab changer changes this but still doesnt load game any thoughts ppls
Justin, I use WAB version changer. I do believe that you need 1.5.
Thank you everyone for your comments! I have only you to thank for saving me from a version 2.0… Cheers.
anyone know where you can download the US Firmware 1.5 not the Japanese one?
Does anyone know if this downgrader will work with the PSP-1006 model? PSP-1006 is the PSP for HK, Singapore, Thailand, Indonesia and the Philippines.
i think the downgrader is an awesome idea, but when i tried to scroll down to the overflow.tiff image, it freezes. after about 10 seconds the screen blacks out. i’ve tried several times, and it does that every time. how do i get it to show the white text instead of just blacking out? andrewtr89@gmail.com
ok for the last 2 posts that havent seemed to work
i would advise not to pull the battery
it bricks your psp
it bricked mine and i am worse than angry
Say No to 2.0 !
Keep the scene alive with 1.5 !
;)
Arizona Glover
http://paulsbaker.blogspot.com/
OMG!!!! WHAT DID I DO WRONG?!?!?!?! I FINALY GOT IT TO STOP FREEXING AT THE “picture file” part and i restarted no error screen….then i went and did the update and pulled the battery and NOW IT WONT COME BACK ON!!!!!! IT JUST SHOWS GREEN LIGHT THEN SHUTS OFF!!!!! WHAT DO I DO?!?!?!
i’ve managed to downgrade and successfully get the emus running. it’s great.
only problem is that i now can’t run some umds without upgrading (so far ‘pursuit force’ and ‘burnout legends’). anyone got any ideas?
I know you can put movies onto the Stick, but is there a way to play multi region UMD Movies on these things? Would be nice to have a movie collection of UMD’s as well!!!
why can i not see overflow.tif picture on my psp and can not downgrade it dose not work Help Help
Hey guys,
I downgraded ok from 2.0.0 but when i checked network settings it downloaded a new upgrade 2.0.1 after reading on here that you could keep browser by doing downgrade a different way so i upgraded to 2.0.1 so i could downgrade to keep browser.
Unfortunately now I am not able to downgrade as it appears sony have added something in 2.0.1 so you are unableto use the downgrade available on here.
You cant even restore the version to 2.0.0.
Any comments?
it worked omg it worked im well chuffed it took some time but after an email to jerrorist in post 86 its all good thanx j
is there no chance to downgrade from 2.01 to 1.5?
what is the problem which keeps me away from downgrade to 1.5? is there anyone who can help me, beeing able to play all i want on that psp?
Yeah i have the same problem as whatthehell, i got 2.01 thinking it was 2.0 just at a glace and now i’m screwed!… or am I? can someone help?
I downgraded with absolutely no problems at all. I was even brave enough to try removing the battery instead pushing O but it didn’t keep the browser… meh. Back to running homebrew! w00t!
It seems Sony has changed the 2.0 firmware on their website to 2.01, so if you think you are going to get the 2.0 firmware from Sony’s website you are wrong. pspupdates.com has it though.
Im from the UK will these hacks work on a british psp, i really want the emulators cos ive downloaded a few good ones, im really afraid incase it bodges up (screws up) can anyone assure me that it works and didnt mess up the first time they did it, i will only do it once and not bother upgrading it, so if anyone can give me the all clear that would be great
I noticed that a lot of mac users PSPs freezes when they try to open overflow.tif. The same thing happened to me even though I re-copied, formatted the memorystick and so on. I got it to work by copying the files from the terminal to the memorystick. Try it. Will probably work!
i don’t have 2.0 firmware and all i can find is 2.01. where can i get this upgrade?
Im from the UK and carried out the ‘down grade’ of the firmware and it all worked fine. I even carried out an upgrade so that I could play Burnout again. Make sure you get your files from a reliable source
i have v2.01 and it doesnt work..dies this matter? if anyone knows can you email me at goped79@gmail.com
hi all, im also from the uk and recieved my new psp today as my last one had a fault. i did the downgrade and like almost everyone it scared the hell outta me when doing it. i did it from http://www.psp-vault.com where there is also alot of helpful comments from others. after i did it, thinking i was stupid for pulling out the battery when the psp froze, i saw this article and thank god that it says to pull the battery out. this article here does it exactly how i did it and includes pics, thanks to the person who posted it!
but i’ve already downgraded and (oviously) i can’t go back to 2.0 from 2.01 is there any thing i can do to get some homebrew running?
I have the japanese psp and i did the downgrade from 2.0 to 1.5 and after like 5 hrs of playing with the nes emulator for psp and some nes roms it got broken, is like keep pressing the right d-pad all the time any ways i still play some psp games that dont need the d-pad at all, so is up to you if you want to do it or not but i think it works beter on the us psps.
ive tried everything on this forum thingo and it didn’t work! can some 1 please help me iam so sad that i cant play emulators! my email is sean_evans666(at)hotmail.com please email me on tips on getting the downgrade to work. plz help me!!!!
if you 2.01 firmware, you are in fact screwed and not in a good way. 2.01 was released by sony to patch the hole that allowed the downgrade to 1.5.
if you have a 1.51 or 1.52 and need the 2.0 firmware, get it from http://pspupdates.qj.net in the files section.
I have restarted my psp many times and all i get is a frozen screen at the photo file. I have tried almost every thing pls help me E-mail me at BradLad@earthlink.net. I have pulled the battery when it was upgrading and it did the same thing as many ppls it wont turn on. I just took it to Best Buy for a replace ment. pls help me