Same thing happened to me.....i decided to call Sony rather then fix it my self.......my warranty expired w eek after i called do i gto lucky

 DONT AND I REPEAT DONT try to open it ur self or sony wont take it.

 I waited two weeks and got it fixed....apparently the thing that reads the discs was fried

so in conclusion just send it to sony ( IF UR WARRANTY IS STILL ACTIVE) and it wont cost u a thing worst case they will send u a new one no charge......