1. Check the memory card slot. Make sure that the memory card is properly inserted into the slot. Try pushing it in and out a few times to make sure that it is making a good connection.
2. Clean the memory card slot. Dust and debris can build up in the memory card slot and prevent the memory card from making a good connection. Try cleaning the slot with a cotton swab and some rubbing alcohol.
3. Format the memory card. Formatting the memory card will erase all of the data on it, but it may also fix any errors that are preventing it from being read. To format a memory card, go to the "System Configuration" menu and select "Format Memory Card."
4. Try a different memory card. If you have another memory card, try inserting it into the PS2 to see if it works. This will help you determine if the problem is with the memory card or the PS2.
5. Contact Sony support. If you have tried all of the above steps and the PS2 is still not reading memory cards, you may need to contact Sony support for help.