6.20tn-d

I have a 6.20TN-D psp go, and trying to get it to 6.20 Pro B-9. I tried using this http://forums.dashhacks.com/f133/downgrading-from-firmware-6-3x-to-firmware-6-t296612/ didn't work and i tried installing 6.20 Pro B-9 straight and that also didnt work. I want to update because there are some...

how do i play PS1 games on my psp 3005 cfw 6.20 TN-D?? any tutorials?? does it brick when it has an error? i mean harmful?