need 3.01 downgrader to 2.0 or 2.80

[sonicboom147]

please i urgently need it

[bah]

No such downgrader exists at this time.
2.71 is the highest firmware from which you can currently downgrade.
All you can do is wait patiently and hope.

Also check to see if your psp hardware is version ta-82 (Image showing how to check), if it is, you cannot downgrade it below 2.5 even if a downgrader that works from 3.01 is released. This is due to it being a newer version of the hardware designed to prevent downgrading.

[michaelp]

one thing you could do to use 1.50 software is devhook and psp dumper and decrypter
here's a guide:
KABOOM! The man himself, BOOSTER, is back with yet another phenomenal accomplishment ¡ª 3.01 firmware emulation via DevHook v0.51. Only days ago v0.50 was made available; now we present you with this earth shattering, mind blowing, wig splitting release.

I¡¯ve yet to personally confirm the stability of 3.01 emulation It is in fact quite stable; feel free to post your experiences below.

Here are easy to follow instructions, courtesy of comment #40, posted by Steven-style:

Remove all previous DevHook files from your memory stick.
Copy the DevHook 0.51 package to the root of your memory stick. This would be ms0:/ and the two folders should be ¡°dh¡± and ¡°PSP¡±.
Download the 3.01 update (search Google) or PSP Hacks.
Get PSARDumper
Extract the DATA.PSAR from the 3.01 update you¡¯ve downloaded with a program such as PBP Unpacker. Once thats done, copy the DATA.PSAR over to the root of your memory stick.
Run PSARDumper on your PSP, once its loaded up press X to dump a sigchecked 3.01. Once its done your PSP will return to the main menu.
Open up your memory stick, you will now see that there is an ¡°F0¡å folder in the root. Move that to the ¡°301¡å folder inside of ¡°dh¡±.
Go into the ¡°301¡å directory, move the reboot.bin into the f0 folder.
Launch up DevHook and go to ¡°FLASH ROM¡± settings, choose install dh to flash1. DO NOT touch any of the other settings unless you know what you¡¯re doing.
Finally, choose ¡°FIRMWARE¡± from the DevHook menu and pick 3.01. Now start DevHook and you should be good to go!
Thanks Steven, and of course BOOSTER ¡ª unbelievable job!

You can also fetch the modified PSAR dumper (to dump/decrypt) and corresponding 3.01 update EBOOT below.

Download:
DevHook v0.51
Modified PSAR Dumper
PBP Unpacker
3.01 Update EBOOT

this guide is also available at PSP Hacks · Hacks, Cracks, Mods, Homebrew, Utilities · Hack Sony Play Station Portable

[fky2005]

I wanna ask is my PSP firmware ver.3.00 can work on the downgrader step like above ??? can downgrader using the guide?????

[bah]

No you cannot, that is a guide for emulating firmware 3.01 through devhook on a firmware 1.5, 2.71SE or 2.71 with HEN-D PSP unit.

There is currently no means to downgrade any psp that has firmware 2.80 or higher, and no means of running homebrew at all on any higher than 2.81. 2.80's homebrew access is limited and must be run through the eloader.