Brasso. Yep, Brasso.
You could spend a lot of money on a really expensive piece of plastic that uses "special cleaners", or you could use this advice instead: »www.burningissues.net/how_to/scr···pair.htm
An alternate opinion, originally from »www.akl-it.com, but no longer available on their site:
quote:
Replace it! Various recommendations and products exist that may actually damage the disc. Record a CD-R backup if the disc is still readable. Order a replacement if it is not.
It is best not to attempt to repair scratched discs, even though "experts" suggest polishing with toothpaste (some even recommend brands!), car polish, or the use of commercial scratch repair kits. Although visible results may appear to be satisfactory, performance in the CD-ROM drive actually degrades. This happens for three reasons.
First, polishing does not actually remove the scratch, but instead replaces one big scratch with many, many small scratches. Although they are not visible to the eye, optical scattering from the multiple scratches reduces the intensity of the laser beam even more than the original scratch did.
Second, polishing locally reduces the thickness of the polycarbonate substrate and consequently modifies the optical path length. This causes focussing problems. The numerical aperture, or f-stop, of the objective lens in the pickup limits the depth of focus to only two micrometers at the critical pit-land surface. Focus servo systems are fast enough to track once-around variations from warped discs, but serious focus problem can occur if the disc is thinned only in a small region.
Third, any substance used to fill the scratch probably has an index of refraction different from that of the polycarbonate substrate, causing optical distortion in the focussed laser spot. This results in jitter, radial tracking, and focus problems.
If the disc is unique and unreadable, then a new draft Standard, ISO/DIS 12024, suggests cleaning using a soft, lintfree cloth and soapy water. The cloth must not contain any particles or hard fibers that could scratch the disc. The cleaning agent must be soap, such as Ivory Liquid; do not use detergents or solvents such as alcohol. Distilled water is best, since tap water may contain impurities that could remain on the disc. Gently wipe the wet cloth in a radial direction, being careful to avoid any pressure on the label surface. Then dry the disc. Do not allow water to remain on the disc.
If the disc is scratched, leave it alone. Avoid waxes and secret solutions that usually increase error rates, even though the visual appearance of the disc seems to improve. Prevent dirt and damage by keeping discs in jewel cases when not in use. Handle them only by the edge; never touch either the readout or label surfaces. Never write on the label surface with a solvent based pen, such as the popular Sharpie. Use only pens with water based inks, and write only on the clear inner ring if possible.
Severely scratched or otherwise damaged discs should be replaced. If they are unique, attempt data recovery in a high quality drive. Well-intentioned repair efforts usually make things worse, not better.
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by climbers 
last modified: 2004-02-21 14:11:15 |
