por lo menos escribe como es el truco para que la gente lo intente probar....
"Ok here's what I did, I have a 1.52 PSP from Europe and it comes with a UMD that has the 2.0 firmware on it. So I put in the disc and started the upgrade, and at the point where it said "make sure the PSP is pluged into an AC adaptor" or something like that I can't remember it word for word. It is the last point at which you can cancel the upgrade. Anyway before I continued I removed the disc and inserted the Midnight Club 3 disc and then continued. Being that it had already bypassed the version check it continued to load the firmware thinking that it was the 2.0. Now I know that this works because I tried it on three of my friends PSPs all 1.51 I tried it on mine first so I wouldn't brick theirs. And all of us can run homebrew cool! I am guessing that this will only work on 1.5x versions seeing as how you can't use the 2.0 disc to upgrade one with 2.0 already on it. I hope someone will find this helpfull."
TRADUCCION: Tienes que tener una 1.51 o una 1.52, el UMD que te viene con la consola EUROPEA para actualizar a 2.0 y el MIDNIGHT CLUB 3 (Supongo que cualquier otro juego original que tenga la actualizacion 1.5 dentro valdra pero no lo se), encender la consola con el disco del UPDATE 2.0 y cuando te digan lo de conectar a la corriente la consola (este momento sera el ultimo para poder cancelar el update) cambia el UMD por el del MIDNIGHT y pulsa a continuar, supuestamente se salta el chekeo de version.
PD: Yo lo he puesto por si acaso suena la flauta y es cierto esto aunque lo dudo y se esta poniendo la peña super pesada con el tema del downgrade. Un salu2