Does anyone know if those Disc Doctor gadgets work?
 

I used to do a lot of travelling and car camping and I have a lot of old CDs in pretty bad shape from keeping them in one of those books with all the CD sleeves in them. My stereo CD plays them fine, but my DVD-ROM is a little more sensitive and gets the jitters on some of them. I've seen at certain stores these "Disc Doctor" type machines that claim to repair CDs, CD-ROMs, DVDs etc. Usually they cost around $30 (U.S.) and I don't know anyone who's tried one. I didn't want to waste the money if these things don't really work, but if they do I'd like to clean up some of these old discs I've got. Has anyone here tried one, or does anyone know more about how these things work: what they can and can't do?

Not sure about those disc doctor things, but the cutting compound based scratch repairers seem to do a decent job if its not too bad.

Something else you can try on a really stuffed disk is Mr. Sheen (or similar), as its silicone based. If you spray on heaps (I mean really drown it) and wait for an hour, then wipe the excess off carefully, it may fill the scratches sufficiently for it to be used again..

I dont reccomend that for anything that isnt totally stuffed already though, as it might make it worse...but it has worked for me on a couple of occasions...

Thanks Atmo. I'll probably try some of that scratch stuff (I've seen it in stores). I'm still curious about the Disc Doctor things, though. They could be really handy if they work.

Also, someone told me that while CD players read the bottom of a disc, DVD players read from the top. Is this true? It would explain why the the DVD-ROM is having problems. One troublesome disc in particular has a lot of scratches on the top.

That's not exactly true - while you can have DVDs with data on both sides it's not possible for the DVD player to read through the top of the CD. Of course if the top surface (including all the shiney metallic bit) is gone then the laser in the player won't have anything to reflect back off of, so the disc will no longer work.

In that case scratches on the top of the disc, given that they're not deep enough to affect the actual metal inside, shouldn't affect the reading of the disc, correct?

A few other questions then: How exactly do scratches in the plastic affect the reading of the disc? Is it because surface errors refract the laser? Also, audio discs read from the center to the outside: is this correct?

You could try using EAC in paranoid mode to rip the CDs to your hard drive. It might take all night but it often does a good job of reading scratched CDs, which you could then run through a WAV editor to remove the audio artifacts. I'd give this a go before shelling out any cash. :)

correct, provided when you look at the bottom of the disc you can't see daylight where shiney metal should be :D

the data is stored on the plastic on the bottom of the disc. The laser shines on the disc and gets reflected off the metal layer in different ways depending on the pattern of the dips burned in the plastic (more technically the dips can either be "on" or "off")

yes, errors on the plastic side destroy the dips making the laser refract in a different mannar to the way it should, thus the data cannot be read.

yes again (infact all CDs are, whether they be audio or data). If you look at the bottom of the disc you will see that the middle of the disc looks different to the edge (this is very noticable if the disc has only 30mins of music).

This is also why you can have the smaller 3" single CDs, and other wierd shapes cut into them.

As dylman says, you should try changing the settings on CDex or EAC to paranoid reading mode, this means that the computer will try repeatedly to read the data, and so has less jitters.

I've just copied the CDs which I want to use in the car, thus keeping the originals safe. Well, that and most of my stuff is on vinyl anyway :D

Re: Does anyone know if those Disc Doctor gadgets work?
 

I've got a Disk Dr and it works pretty well.

You put the disk on the tray, spray it with some spray that came with it, and turn the handle to spin it around and it spins in the tray to clean it.
It works good for small scratches and fingerprints, but not deep scratches.

Hey. It works on tv so it has to work in real life. :D