ignore the others mate.
http://www.psp-hacks.com/2007/01/02/280-to-271-downgrader-released/
Downgrader from 2.80 to 2.71 for any motherboard TA97-TA86
from there you can then run Dark_alex's 2.71 downgrader to get to 1.5
http://www.psp-hacks.com/2006/12/27/ta-082-downgrader-released/
from there you can install 3.02OE-A then upgrade that to 3.02OE-B so you can play PSX games and all homebrew etc
my psp may be broken but i like to keep up with the psp news
/ 
