The laser on a PSP is a small internal component that reads the discs you put into the unit. If your PSP isn't reading new discs, or is constantly freezing and stopping, chances are the laser is dirty or damaged. The good news is that it's possible to fix the laser on your own, but unfortunately it will require the full dis-assembly of your PSP. Luckily, the process of disassembling your PSP is fairly straightforward even if you aren't particularly tech savvy.
Turn your PSP off and remove the battery door from the rear of the device. Then remove the battery from its compartment.
Use your Phillips screwdriver to remove the two screws in the battery compartment, the two screws on the opposite side of the back of the PSP and then single screw on the bottom of the PSP.
Pull the front plastic faceplate from the PSP by the seams where it connects to the body of the unit. The LCD will now be exposed.
Lift up the button bar located directly below the LCD screen and remove it. Then use the tip of your flat-head screwdriver to pop the four metal tabs on the corners of the LCD screen up.
Lift up the PSP screen and unplug the orange connector ribbon from its port on the main circuit board. Remove the screen and set it aside.
Remove the screws holding the metal screen guard over the circuit board. Then remove the guard and set it aside.
Unplug all cables that connect to the green circuit board and remove the single screw located on the top right side of the board.
Locate the yellow power socket in the bottom right corner of the circuit board and remove the single screw above it. Set the power socket aside.
Lift the motherboard out of the housing and the laser assembly will be exposed in a metal frame in the PSP housing.
Remove the four screws on the corners of the laser assembly and lift it out of the unit.
Open the metal frame and make sure the laser is securely attached to the back of the housing. If not, use your screwdriver to tighten the screws next to the laser.
Use your can of compressed air spray the face of the laser to remove any dirt or debris that may have been hindering its performance.
Place the assembly back in the PSP housing and reassemble the unit in the reverse order you took it apart. Your PSP laser should now be working.