Error Screen
If your PSP shows the standard "Contact customer support" error screen while you're trying to play a game, you can attack this problem a few different ways. Start by powering down your PSP and turning it back on to see if the error screen is still visible. If so, take the back off of the PSP and remove the battery. Leave the battery out of the PSP for 2 minutes before replacing it. Turn the PSP on to see if the error screen is still there. If it is, something is wrong internally with the PSP, and you need to contact Sony customer support.
If the error screen disappears, attempt to continue your game. If the error message comes up again, the problem most likely lies with the PSP battery or the game you are using. Try playing a different game, and if the error screen continues showing up, the problem is with the battery, which you need to replace. If the error message shows up only for a particular game, try using a different copy of the same game. If you continue to get the error message, the cached files saved in the battery are the cause; in this case, the only solution is to purchase a new battery, because Sony has not yet released a method of altering these cached files. If the error message doesn't show up again, the issue is with the copy of the game you have.
Unable to Read Disks
If your PSP is unable to read game disks, a few different things could be causing this common problem. First make sure that the disk isn't dirty or damaged; try running it in another PSP if you can. If the disk isn't dirty or damaged, the PSP is causing the problem. A number of issues could be affecting your PSP: the UMD motor is malfunctioning, the laser has grown weak, the UMD tray is bent or something is stuck in the UMD drive. If you turn the PSP upside down and carefully slide the tip of a cotton swab in, you can remove anything lodged in the drive; however, to repair the laser or drive motor, you need to contact Sony customer support or another technical repair shop to service your PSP.