My PS2 (well actually both PS2s I've owned) both had disc read problems, but that's not here nor there.
If you have a 3.0+ and don't care about homebrew or hacking, I would send the PSP to Sony and they will fix it. I knew somebody who was having the exact same problem and he sent his PSP to Sony and they fixed it.
If you (like me) love homebrew and all, your best bet might be to have it repaired. I know there are sites (not off the top of my head) that can repair PSPs.