if you have a busted PSTwo with a fried laser (you can tell by smelling on it and you feel the scent of Electronics) your laser isnt busted but your laserlens is melted and thats why your machine cant read discs. where you can find replacement lenses i dont know yet. but i think i know why they burn.

some people use SOMEONE's fix to correct the laser from busting but by accident they lift one of the components the 4.7k ohm resistor goes too and this causes a laser burn.
if you cause a lift on the other point where the 2.0K / 560 Ohm goes it will cause your laser to go back and forward and not be able to boot discs.. if this happened and your laser havent fried try removing the fix and replacing the components. (components marked 303 are actually 30K ohm resistors, and components marked 683 are 68K resistors) im not quite sure but ive heard a rumour that you could replace one of the values to the newer ones for a better read value and more stable unit. (unverified at this point)