View post (Howdyou unscrew CDs?)

View thread

Lordathestrings
Gear Guru
Joined: 01/18/01
Posts: 6,242
Lordathestrings
Gear Guru
Joined: 01/18/01
Posts: 6,242
10/20/2003 8:07 pm
The short answer is "Get new CDs".

The data on a CD is read by aiming a narrow laser beam at the track of pits burned into the vinyl substrate of the disc. A smooth area between pits reflects the beam, so the photodiode detector 'sees' it. A pit scatters the beam, so very little of the light reaches the detector. This ON/OFF is interpreted as the 1s and 0s of the digital data. The reflective surface is covered with the same vinyl material as the substrate, to protect it. Scratches scatter the laser beam the same way a pit would do, so the detector gets false data. Unless the scratch is fillled with the same material as the prtective vinyl surface that has been scratched, the laser beam is still going to be scattered. I haven't heard of any repair kits that are truly successful at restoring damaged CDs.

So the long answer is "Get new CDs". And handle them carefully. The vinyl LP record technology gave us old farts a good background in proper handling techniques. Don't touch the data surface. Don't wipe them unless you have to, and then be very sure to stroke from centre-to-edge, so any scratches you cause will not run parallel with the data tracks.



[Edited by Lordathestrings on 10-20-2003 at 03:09 PM]
Lordathestrings
Guitar Tricks Moderator

www.GuitarTricks.com - Home of Online Guitar Lessons