James Delahunty
1 Sep 2006 19:32
Once again, through the excellent (and voluntary) work of PSP coders (Dark_Alex & Mathieulh), another PSP firmware downgrader has been released. This time, the v2.71 firmware can be downgraded to the homebrew-friendly v1.50. It utilises a recently exploited vulnerability in the tiff library to launch the "downdater".
Some weeks back, a downdater was released for both the 2.50 and 2.60 firmware versions. This new downgrader for 2.71 is basically a port of that downdater but a copy of (unpatched) Grand Theft Auto: Liberty City Stories is not needed like before (that particular hole was closed after 2.60). Like the 2.50/2.60 downdater, you should NOT try this if your PSP has a TA-082 motherboard.
To downgrade, not only will you need your 2.71 PSP, you will also need to find somebody with 1.50. This is simply because you need them to run homebrew that will dump their flash and some files form the actual 1.50 eboot update file. You wont find these files on PSP sites as it is illegal to distribute them. The files will be dumped to the Memory Stick (DOWNDATER folder appears in root).
Once a v2.71 user has these files downgrading is now possible. Of course, don't expect the friendly Sony update screen this time. What you will get instead is a fully red screen while files are being taken from the Memory Stick.
More Info: pspupdates