i think u need a pandoras battery but in order to get one u need an already hacked psp :/ theres a bit of irony for ya
That's outdated information, you don't need another CFW PSP to downgrade. But you DO need a Pandora's battery and a MMS. Search for a guide on creating a Pandora Battery if you don't already have one. Alternatively, you can buy a TOOL battery (such as Datel's one) if you don't mind spending a little cash. First thing to do, though, would be creating your MMS. Go here and download the TOTALNewbi-easyInstaller: http://dl.qj.net/TOTALNewbi-easyInstaller-PSP-Tools-Utilities-(on-PC)/pg/12/fid/14749/catid/193 Follow the instructions to create your MMS. That means you need to format the stick on your PSP first (scroll all the way to the left on the XMB and find the Format Memory Stick option, backing up any data to your PC first using USB mode if you want to keep anything). Once your MMS is created, you can flash your 3.80 to CFW, then downgrade to 1.50. There's undoubtedly tutorials for that somewhere, but take it one step at a time.
Moved to mod & firmware forum. @shamster Check out the stickies there - you'll find all you need. edit to add: Take out the email address in your sig shamster - not allowed here. You can also post that WTB question in the Aferdawn MarketPlace.