The old phat PS2s had a problem where they would stop reading discs after a couple if years. Had two stop working like that. The problem would start slow, only affecting a few games at a time till they were all unplayable. Opening up and cleaning it was a temp fix, but it only worked a few times before that stopped working too.
Ever since that I have real bad OCD with my consoles, drives my wife nuts. However my phat PS3 and 360 still work to this day.