Wow, a little over a week ago we saw a "Hello World" application emerge on all 2.0-2.80 PSP's with the newly discovered and exploited libtiff vulnerability. In the past week we have seen both a 2.71 downgrader, 2.80/2.81 decrypter, and a new eLoader (v0.9.8), all of which happened within days of each other!

Today, the Noobz team have released a 2.0/2.01 downgrader that utilizes the new tiff exploit which allows them the necessary access to complete such a task. Even though 2.01 was released roughly a year ago, I'm sure there are still those who may benefit out of this knowing that this is a safe downgrader and hasn't been reporting any bricks so far.

As always, downgrading always has a risk of bricking your PSP if you fail to follow the directions properly, so please use this downgrader at your own risk. So, for those who didn't update to 2.71 to downgrade, you can successfully downgrade by following these steps as listed in the readme file -

1. First you need eLoader 0.98 or later (get it from www.noobz.eu).
2. Install eLoader, and make sure that it is working for you by loading some nice safe homebrew (e.g. Squarez).
3. Next unzip this downgrader package onto your memory stick.  You should end up with the EBOOT.PBP file copied to /psp/game/201downgrader/EBOOT.PBP.
4. Also copy the v1.5 Update EBOOT to /psp/game/update/EBOOT.PBP.
5. Now run the downgrader via eLoader.  Assuming that your PSP passes the safety checks, you should be given a menu of options.
6. To downgrade, you need to select the 'set to v1.00' option (the Circle button).
7. This will fake your PSP to version 1.00.  Once you've completed the process, you can run the v1.5 Update EBOOT, directly from your PSP's Game menu.
8. Note that when the v1.5 Update is 99% complete, it will display an error message that it has 'failed - contact Sony customer support, error code FFFFFFFFF'.
9. This is OK!  Just power off your PSP, and reboot it. You then get a blue screen, saying "Press O to reset your settings" in several languages.  Press O, and your PSP reboots again - voila! You now have a v1.5 PSP.
10. Note that, before you install the 1.5 Update, your PSP is still really a v2.0 or v2.01 PSP, but it will claim to be v1.0.  If you've changed your mind about downgrading, you can choose to rerun the downgrader, and restore your old version number, with either the Cross or Square button, as appropriate.
11. Alternatively, if you changed your mind about running the downgrader, you can just press Triangle to exit without changing anything.

Download: [2.0/2.01 Downgrader]