How do I upgrade my PSP CFW?

How to upgrade from PSP CFW 3.71m33-2 to 3.90m33??

• I am currently running my psp slim with custom firmware 3.71m33-2 and want to upgrade to 3.90m33.I got the sony official firmware from psphero.com and dark alex's 3.90m33 too. can ...show more

• Answer:

  In this process, your PSP 99% of the time will NOT brick. But if it does, you can get this program from the following link and put it in PSP/GAME. You are going to move the RECOVERY folder there. http://dl.qj.net/Recovery-Flasher-v1.30-PSP-Homebrew-Applications/pg/12/fid/23008/catid/151 You will also need to download the 3.71 Firmware and 4.01 Firmware and put it in RECOVERY from here: 4.01 EBOOT http://rapidshare.com/files/130567598/401.PBP 3.71 EBOOT http://rapidshare.com/files/130567593/371.PBP Names should be correct. Anyway, this is how to do it. Put the 3.90 M33 Upgrade folder in PSP/GAME. Put the 3.90 EBOOT at root of memory Stick. Go to PSP and run Update. Follow instructions to install. When it says finished installing, restart required, YOU MUST PRESS X OR YOU WILL END UP WITH A BRICK. If you end up with a brick anyway, make sure program is in memory stick, go to recovery menu, find run program option, and select install whichever firmware you want to. do not save the settings when it gives you that option.