So I have two questions to ask first...
Is the PS3 not working?
Or
Is it not reading discs?
If it's not reading discs then congragulations beucause your blu-ray reader just wore out. Happened to my old PS3. This is common with the larger PS3s becuase there older.
Or if you mean the disc isn't loading all the way, then yor blu ray is staring to ware out. Also happened to my PS3.