This has specifically happened on a few of my XBox360 DVD games but I figure the principle is the same with CDs and DVD movies and just wanted to see if anyone had any ideas

Basically I got some read errors...opened the tray, took out the disc...it had what appeared to be a small (~5mm long x 1mm wide) scratch...but it was actually just some kind of dirt/residue...I was able to wipe it off with 4 or 5 rubs on my tshirt but the buildup of dust or whatever temporarily caused read errors...wiped it off and it seems to work ok

I guess my main question is what causes this? Is it a dirty laser? Dirty 360? Is the 360 just a crappy system? Scratches just seem to make more sense to me than this concentrated buildup of dirt over one small space...any ideas?

8/21/2007 4:08:33 PM

Everytime you handle DVDs you deposit oil from your skin. That oil attracts dust and dirt.

When the DVD rotates inside at VERY high speeds, various centripetal forces work on it thereby concentrating all the oil/dust to one spot or even a line.

8/21/2007 5:33:07 PM

that seems to make sense from a biology/physics perspective i guess

i always try to handle the discs by the edges but i guess some amount of oil is inevitable...just seems kind of odd how the particular spot is near the middle of the disc (between middle hole and outer edge)...centrifugal force would suggest it maybe closer to the outside but i dont know

8/21/2007 5:35:07 PM

Centrifugal force is a pseudo force used to explain the counteracting effect to the centripetal force.

You can mathematically calculate only the centripetal force, and then equate it to the imaginary centrifugal force to explain a stationary object on a circular plate.

8/21/2007 5:39:16 PM

keep in mind though, I am specifically talking about a 360 which have obviously had problems

I don't know if I've ever seen this on any DVD movies (played in a non-360 player) or CDs

8/21/2007 6:17:44 PM

They don't rotate as fast as games do in the 360.

8/21/2007 6:18:28 PM

8/21/2007 6:20:05 PM