Things You'll Need
Instructions
Remove the black plastic covering from your PSP. You can find four of the screws on the back panel and the fifth on the bottom edge under the screen. Keep the screws in a safe place, as they are small and easy to lose.
Unscrew the screen's metal casing from the front side underneath the covering. The UMD drive door should automatically open at this point since the closing mechanism will be released.
Check that the spring behind the door is still in the small groove. If it has moved, set it back into place with a pair of tweezers. The spring slipping out of its groove can often make it seem like the "Open" button is malfunctioning, so check this before removing the "Open" button itself.
Check that the "Open" button is lined up with the plastic slider that manipulates the spring. Use your tweezers to put it back into place if it jumped over the metal tag.
Make sure that the "Open" button is aligned in its spot. Then replace both the metal casing and black plastic cover. Use a couple of different UMD disks to make sure that the drive opens both when empty and with disks inserted.