why dont you check if the ps2 still works without it and if it doesent
open up the ps2 and see if it fell in there. to open the ps2 look at the bottom of the ps2 you will see five squares take them out using a chisel or something and unscrew the screws then open the ps2 by pulling from the sides becareful with the power button you might squish it putting back the tray, but anyways look around the inside of the ps2 and see if it fell in there. oh and im talking about the new thin ps2. i dont know if the big ps2 has the same procedure opening it up but anyways thats all i can say.
Hasan
May 2005