dvd data failure

The more data you can put on a disc, the more delicate it is.

CD's have a protective layer, dvd's do not. I really doubt any
polishing will help.

On 4 Aug 2006 07:04:29 -0700, "Xiaoding"
wrote:

The more data you can put on a disc, the more delicate it is.

CD's have a protective layer, dvd's do not. I really doubt any
polishing will help.

No, that's backwards.
In fact, DVDs have an extra layer of polymer that CDs don't have.
http://www.videointerchange.com/dvd....20Construction
Ijn CDs, that polymer coating is missing; there's just a lacquer
coating, which is just a place to put a label and offers little
protection.
http://www.mfdigital.com/2004/06/cd-construction.html
--
Bill Funk
replace "g" with "a"

Bill Funk wrote:
On 4 Aug 2006 07:04:29 -0700, "Xiaoding"
wrote:

The more data you can put on a disc, the more delicate it is.

CD's have a protective layer, dvd's do not. I really doubt any
polishing will help.

No, that's backwards.

Yes, Bill is correct, DVD's are technically better, but it really
depends on the scratch resistance of that layer, which is where the
cheap disks tend to fall down.

But just for the record I think the worst disks I ever used were some
cheap 'Princo' CD's - not one of them is readable after 1.5 years. Not
because of scratches - the data layer has gone a weird yellow colour
and they are completely unreadable.

And the polishing bit is backwards too. I have successfully used
automotive polishes to recover unreadable disks, both cd and dvd, on at
least 4 occasions in the past. It is most definitely worth a try if
the scratches are light. Don't use 'heavy cut'!

No, that's backwards.
In fact, DVDs have an extra layer of polymer that CDs don't have.
http://www.videointerchange.com/dvd....20Construction
Ijn CDs, that polymer coating is missing; there's just a lacquer
coating, which is just a place to put a label and offers little
protection.
http://www.mfdigital.com/2004/06/cd-construction.html
--
Bill Funk
replace "g" with "a"

While true, it's still more delicate than a CD. Why are TDK and
Memorex spending millions to develop better coating technology?
Because DVD's are prone to failure from scratching. They would'nt be
spending big bucks if the problem was not there. You can get CD's with
polymer coating, but CD's are good as is anyways. DVD's are not.

Hello again Bart and other responders,

I downloaded the free infinadyne progr. and it only recovered 7 out
of c.570 files,BUT when I then clicked on the standard/integral disc
reading progr. on the computer it was able to read ALL of the 570
files, and I recovered them all to CDs ,I don't trust DVDs anymore.

I have since tried to read the DVD again, and the computer cannot
find any files on it .
So I was very lucky.
Very illogical/temperamental these computer systems I think.

Hartly

Bart van der Wolf wrote:
wrote in message
oups.com...
I have stored computer data on four dvd+r discs.
They all seem to have failed,that is one is not even recognized as
a
disc by the computer, and half the files have gone missing from the
others.
They have scratches on them.

Why and how? Disks don't come with scratches, so how were they caused?
The direction of the scratches is also important for your chances of
recovery.

Do you have multiple back-ups (I assume not)? You should not put all
eggs in one basket, but use a certain redundancy in your back-up
method.
Best approach is to start at the beginning, and use a first class
recorder and matching media. Companies like Plextor also provide media
compatibility data, and their better recorders come with software that
allows to detect degradation long before the stage of unreadable due
to aging arrives. Mechanical deterioration effects can be overcome by
using a non-archive copy as a working disk.

The free versions of cdroller and isobuster will not recover the
lost
files.

Try http://www.infinadyne.com/cddvd_diagnostic.html as what may be a
final resort. The demo will allow you to see what can be recovered,
you'll then have to purchase it to actually do the recovery.

Is there anyway I can access these files again?.

How much is data worth to you, literally in hard currency? There are
specialized companies that can come a long way is restoring, although
mechanical destruction is the hardest kind, and therefore is better
prevented.

--
Bart

On 7 Aug 2006 07:00:08 -0700, "Xiaoding"
wrote:

No, that's backwards.
In fact, DVDs have an extra layer of polymer that CDs don't have.
http://www.videointerchange.com/dvd....20Construction
Ijn CDs, that polymer coating is missing; there's just a lacquer
coating, which is just a place to put a label and offers little
protection.
http://www.mfdigital.com/2004/06/cd-construction.html
--
Bill Funk
replace "g" with "a"

While true, it's still more delicate than a CD. Why are TDK and
Memorex spending millions to develop better coating technology?
Because DVD's are prone to failure from scratching. They would'nt be
spending big bucks if the problem was not there. You can get CD's with
polymer coating, but CD's are good as is anyways. DVD's are not.

No, a DVD isn't more delicate than a CD. On the burning side, it has
the same protective layer that a CD has, with the added protection of
another layer on the label side.
--
Bill Funk
replace "g" with "a"

"Bill Funk" wrote in message
...
SNIP
No, a DVD isn't more delicate than a CD. On the burning side,
it has the same protective layer that a CD has, with the added
protection of another layer on the label side.

However, due to the higher data density, wouldn't it be logical that a
DVD is more susceptible to optically induced failure caused by
scratches?

--
Bart

On Mon, 07 Aug 2006 07:48:22 -0700, Bill Funk wrote:

While true, it's still more delicate than a CD. Why are TDK and
Memorex spending millions to develop better coating technology?
Because DVD's are prone to failure from scratching. They would'nt be
spending big bucks if the problem was not there. You can get CD's with
polymer coating, but CD's are good as is anyways. DVD's are not.

No, a DVD isn't more delicate than a CD. On the burning side, it has
the same protective layer that a CD has, with the added protection of
another layer on the label side.

I think that what's meant is that DVDs are more delicate because
some scratches on them that cause data loss might be tolerated on
CDs. Data loss on CDs might require deeper or greater numbers of
scratches.

On Mon, 7 Aug 2006 19:39:08 +0200, "Bart van der Wolf"
wrote:


"Bill Funk" wrote in message
.. .
SNIP
No, a DVD isn't more delicate than a CD. On the burning side,
it has the same protective layer that a CD has, with the added
protection of another layer on the label side.

However, due to the higher data density, wouldn't it be logical that a
DVD is more susceptible to optically induced failure caused by
scratches?

Possibly, but I've seen no studies that have shown that.
--
Bill Funk
replace "g" with "a"

On Mon, 07 Aug 2006 13:44:24 -0400, ASAAR wrote:

On Mon, 07 Aug 2006 07:48:22 -0700, Bill Funk wrote:

While true, it's still more delicate than a CD. Why are TDK and
Memorex spending millions to develop better coating technology?
Because DVD's are prone to failure from scratching. They would'nt be
spending big bucks if the problem was not there. You can get CD's with
polymer coating, but CD's are good as is anyways. DVD's are not.

No, a DVD isn't more delicate than a CD. On the burning side, it has
the same protective layer that a CD has, with the added protection of
another layer on the label side.

I think that what's meant is that DVDs are more delicate because
some scratches on them that cause data loss might be tolerated on
CDs. Data loss on CDs might require deeper or greater numbers of
scratches.

Possibly, but, personally, there are too many "mights" there to base
anything on.
:-)
--
Bill Funk
replace "g" with "a"