PSP will not read mem sticks anymore

So I haven't played my PSP for a few weeks, and then I noticed that the Dissidia Final Fantasy Demo was out. So I switched on my PSP, and what do I find? It says that I do not have a mem stick inserted. When I clearly do. So I tried my other mem stick.....same thing. I even took out the battery and blew air on the battery and inside the PSP. And still, nothing works.....Does anybody have any idea how to fix it? It worked perfectly a few weeks ago.:?

I don't know you can try the following:

Try formatting one of the memory sticks through the computer and try again.

Try cleaning up the metalic plates on the memory stick.

Hope that helps.

I got it to work! For some stupid reason I had to hold the mem stick in a little longer than you normally do when you insert it.