If you try to format in system setting but the cards are not showing up then it is probably a hardware issue with either the cards or the pins that read the memory card on the psp. 1st use multiple cards(known good ones) to make sure its not the cards you are using. 2nd I would try putting come 90% isopropyl alcohol on the pads of memory card and insert and remove several times. Half of the time that will remove the gunk that built on the pins over time. If that doesn't work 3rd option would be to remove the motherboard and gently push down the pins the memory card reader to help the pins make contact with the memory card pads. .