DVDs that become unreadable? How?

[Dog80]

In this pit thread http://boards.straightdope.com/sdmb/showthread.php?t=263473 I pit Dixons and their cheap DVDs(-R I think).

As time passed, my dvd drive would need an increasing amount of time and effort to access the burned DVDs. After a month or so, the DVDs became totaly unreadable. Now, in two of them I can simply see the file list, but I cannot copy any files (returns a CRC error).

I had this thing happen before with a cheap CD-RW disc, but how the heck is that possible with DVD-Rs?

[Q.E.D]

Probably a combination of factors:

These discs use gold, silver, or a silver alloy for the reflective layer instead of aluminum as in ROM discs. Gold will not corrode but is expensive. Silver is more reflective and cheaper than gold but is susceptible to corrosion if exposed to sulfur dioxide, an air pollutant that can penetrate the disc in the same way oxygen can—with moisture. Manufacturers use various silver alloys to help inhibit silver corrosion, and most R discs available today use a silver alloy reflective layer. The chance of silver corrosion from exposure to sulfur dioxide is less than the chance of aluminum oxidation caused by high humidity. Nonetheless, keeping the disc in a filtered “clean air” environment can minimize or eliminate its exposure to sulfur dioxide. With proper storage, these discs will outlast the technology.

…The organic dye used in the data layer of R discs degrades naturally but slowly over time. High temperatures and humidity will accelerate the process. Prolonged exposure to UV light can degrade the dye properties and eventually make the data unreadable. Heat buildup within the disc, caused by sunlight or close proximity to heated light sources, will also accelerate dye degradation.

From here.

[Dog80]

@Q.E.D.

Probably a combination of factors:
From here.

Can that happen in just a month’s time? They must be the crapiest DVDs ever. :mad:

[Tim_T-Bonham.net]

I know that it’s been shown that a lot of CD-R’s recorded on computers fail due to people putting those self-adhesive labels on them. Apparently something in the glue reacts with the coating on the CD-R’s, and they fail pretty quickly (within a few months to a year).

This was covered fairly extensively in Fred Langa’s column. (The site’s down right now due to a server move, but normally you could search at http://www.langalist.com/ to find the info.

I’d guess that DVD-R’s could have the same problem.
Did you put a label like that on this DVD that you burned?