[japc]

Hi there.

I have a CD (well, in reality several but let's focus on this one) with a visible somewhat nasty scratch. From the several CD players I have at home (none of them very good by the way): a sony hi-fi, the drive from the thinkpad and 2 sony portables, only one of the sony portables doesn't skip badly on the scratch, if I didn't knew I would say it had no scratch at all.

How can this be explained? Calibration? Laser? Is there any documents explaining this? Is it fixable? Should I do it? Are there sensibility tables I can consult? Or is it kind of random, varying even within the same player model?

On the same subject, anyone with experience on removing scraches? (I've read that white toothpaste or metal polisher do a good job at that)

Thanks.

 

[japc]

shameless bump!

 

[Uncle Erik]

The CD player bounces a laser off the disk. When there is a scratch, the laser light does not reflect back into the sensor correctly. The player won't see that information, which is why it skips.

There are ways to repair the discs. You can find scratch removal kits and CD resurfacers on eBay. One record store I visit has a machine that refinishes CDs - you can pay them to refinish scratched CDs. I have had luck polishing out scratches with Brasso. I don't know if that brand is available outside the US, but it is a liquid brass polish. I would think you could find something similar.

 

[japc]

Yeah. I know how CD readers works and how scratches bring misfunction what I don't know is what to make of diferent readers having diferent behaviours.

Yes, been reading of brasso, that it's the most efective mac-gyver-ish solution. Must try.

 

[Michgelsen]

I think that some players use heavy error correction when they encounter an unreadable piece, and some just skip it.

 

[japc]

Then my brain also did some corrections of his own because I didn't find anything missing or indicative of a non pristine CD on the player that didn't skip.

 

[haarvi]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif The CD player bounces a laser off the disk. When there is a scratch, the laser light does not reflect back into the sensor correctly. The player won't see that information, which is why it skips. There are ways to repair the discs. You can find scratch removal kits and CD resurfacers on eBay. One record store I visit has a machine that refinishes CDs - you can pay them to refinish scratched CDs. I have had luck polishing out scratches with Brasso. I don't know if that brand is available outside the US, but it is a liquid brass polish. I would think you could find something similar.

Uncle Erik
Can you please go over the procedure you use for polishing out scratches on CDs.
Any special type of cloth used as applicator?
Amount of brasso applied?
Rubbing / wiping from inside to outside?
Or....any other tips?
When would you try to mend a CD yourself rather than go to your local shop to have them use their 'professional' approach.
Thanks.
BTW:
Amazon sells equipment designed to remove CD scratches.
Reading the feedback experience with the various machines, may help one select from among the offerings.
Harvey

 

[japc]

Brasso did wonders. The skipping CD doesn't skip anymore, the scratch is not even visible, maybe it wasn't that deep after all.

It was very quick so I took some time to try it also on a CD that was forgotten on the car's glove compartment between two jewel cases, It was scratched to the point I couldn't seem my reflection on the surface and it wasn't recognized on any player. After a light scrubbing it doesn't seem the same and it plays alright.

Have a 3rd but that one with a seemingly deep scratch, I was working on it for a while but quit for today, maybe it's a matter of time. Will try again tomorrow.

I didn't use the liquid Brasso, used the one that seems like cotton soaked in liquid. Put an old magazine on a table, put the CD over it with the playing surface turned up, check if the CD stood quite while I worked it, then I scrubbed (a bit of brasso "cotton", just enough to cover my finget) on the area of the scratches (on the second CD it had to be all the surface) really hard for a while, then cleaned and examined.

Did follow the rules of rubbing from the center to the outer disk but because that made it perpendicular to the scratch and I though it was more logical that way. On the second CD rubbed on a totally random way.