PSP 3000 slim , 4.21 firmware how to downgrade?

[leon_belmont]

Well my cousin just bought a PSP 3004 slim in Italy,but it came with 4.21 firmware and no one offers to hack it. Is this unhackable or what ? Already fixed it by myself .thanks

[cibomatto2002]

You do not need to Downgrade anymore

All-In-One 5.03 GEN-A Installer by Skyline969

Forum member Skyline969 has released another all-in-one installer this time for PSP-2000 & PSP-3000 users who are looking for an easy all in one Custom Firmware 5.03 GEN-A installer. Its straight forward an easy aimed at new users who can let an install do all the work for them. All you need to do is point the installer to your PSP memory card.

All-In-One 5.03 GEN-A Installer! Included is all the tools you need to get your PSP to boot to 5.03 GEN-A custom firmware. Keep in mind that if you shut off your PSP or lose battery power, the firmware is gone and you have to re-load it (but NOT re-flash it). However, to work around this, just put your PSP in standby. It won?t hurt your battery, no worries.

The tools included are:
Official Firmware Update to 5.03
ChickHEN R2
5.03 GEN-A Installer/Loader

Instructions and credits are included in the installer.

http://forums.pspslimhacks.com/hacki...installer.html

I will tell you this if you install anything higher than 5.03 you will not be able to use this