i know how to open it, and i know where the ico4 chip is. The problem is the pin. if you look at all the photo’s i can only see 4 pins but the 5th is the one to cut. (http://i132.photobucket.com/albums/q32/iam7805/DSCF2043.jpg) i have a 1800 original (fat) battery that came with the psp.