That link is for the old PSP versions.
http://www.mr-vizitkin.ru/images/stories/psp_fuse.jpg
^^ Fuses for PSP GO.
The one on the right is for Audio - so the one *under* the metal shielding may well be your power Fuse. I would suggest testing with a multimeter to confirm.
I have ordered some DS F1/F2 power fuses to see if they are compatable but i dont believe they are rated the same.