My advice is to check to see if the laser fires at all. All you do is take apart the ps3 up to the point you see the lens and then you make sure everything is still connected and fire up the ps3 and trick it into thinking a disc is being inserted. You should see the lens flash a purplish color.
In that case then it is probably the lens. If you don't then the laser is probably bad. I just replaced my entire optical deck. What you see the guy in that vid doing is just swapping the mother board of the optical drive. I actually replaced the laser and the rail it sits on. I think this would be easier money wise. Plus I don't know any place that sells entire drives.