I have a cd player that sometimes makes screeching noises when playing discs. It doesnt happen all the time. I had it in the repair shop because it was skipping some (and told them about the noise), and they replaced the laser. It doesn't skip anymore but the screeching sound remains sometimes. What could be causing this? The shop has a 90 day warranty on their work, and will be taking it back soon. Would like to know whats causing it so I can explain the problem better.