i heard that the only way to hack the psp 3000 model is to buy a special battery to boot into service mode. i hacked a psp 2000 model the way i hacked a 1000 model. the way i did that was i had a hacked 1000 model and used the UPMS installer to turn the battery into a pandora battery then i just crammed the battery in the psp slim and it work, so why can't i do the same with the psp 3000 model?

probably because they changed the hardware in the psp and added new security fetures to prevent you from using the Pandora battery technique my advice would be to not update your firmware at all and wait until they finally are able to hack the psp I like to check qj.net mostly to check for updates but a quick search in google wouldn't help.