Dead or stuck pixels may be the result one of two problems which may be able resolved using a psp pixel fixer. You can download the pixel fixer from http://www.psprepair.net/pixfix.rar

The pixel fixer causes all the pixels on the lcd to change colors very rapidly. This process usually resets a dead or stuck pixel. In the event that does not solve the problem, you may contact sony and inquire about a warranty replacement, however the process is not set in stone, and you may or may not be eligible for a warranty replacement.

If your psp is out of warranty, then you will have to decide how much of a inconvenience actually is and if it warrants replacing the lcd.

Parts are available at http://shop.psprepair.net