My unit also stopped working, displaying "cannot read disc" on every DVD. It sounds as though I have a $400.00 hunk of garbage because of Sony's design flaws.

2 things Non techs can do is, clean the lens, and check the Belt(s).
It happens more times than you would believe and is an easy fix.
Beyond that, you will need a meter.

I have the same issues with the cannot play problem. Sometimes it plays and then dies again. I checked everything and cleaned the laser and checked the belt to no avail. I intended to give up and buy a Blu-ray carousel only to find out that they have been discontinued, so now all I'm left with is a 400 disc storage unit.