1. what type of psp do you have? not all can softmod batteries.
2. if you have no memory card inserted, pull the battery and replace it, does it power on automatically?? if not, it's not a pandora.
i also have a few options how to softmod in my Gen guide, 2nd link in my sig...hellcats would be your best bet. install hellcats, also in my guide, open it and it'll auto detect the battery state.
if it says "make normal"...it's a pandora
if it says "make pandora"...it's normal