The purpose of this guide is to explain some of the problems that can occur with DVDs, and possible ways to avoid them.
The biggest problem with DVDs is their vulnerability to scratches and damage to the recorded surface. At least with video cassettes the tape was within a plastic housing, and not exposed.
Most discs that have numerous surface (i.e. light, non too deep) scratches can still be read in most players without a problem. Usually, it's not until they suffer a deep gouge that they will start to skip/jump or freeze during play.
The best, and simplest, way to avoid scratches is to put the disc back in its case/cover whenever it is not in your DVD player. Do NOT leave it laying on a table, or on top of the TV, etc. Also, NEVER let children handle DVDs until they are old enough to understand how to handle them properly. Undoubtedly, younger kids will touch the disc surface, and often with grimy or grubby fingers. Not only is this bad for the disc, but you also do not want foreign matter inside your DVD player.
If you have a scratched disc, there are some domestic repair kits available that might help (check your local Tandy or Dick Smith). Otherwise, go to a video store that has a professional disc repair machine, and ask if they can repair the disc for you. Expect to pay around $5 for the service.
Important: Don't assume that the ONLY reason a DVD won't play properly is due to scratches. Below are some other problems that can occur with DVDs.
Most DVD movies are dual-layered, and this causes a big problem with some cheaper DVD players. They have a problem during the "layer transition" (where the laser switches from one layer on the disc, to the other), which will cause the player to either freeze, skip to another scene at random, or seize up completely.
The layer transition will occur at a place, chosen by the disc manufacturer, usually past the halfway point within the movie. There are websites that mention the exact transition point for many DVD movies (e.g. www . michaeldvd . com . au) if you need to verify that is your problem.
There is no way to overcome this problem, but if you find your machine doing it too often, a better brand (more expensive) machine might be on the cards.
Fingerprints, Dirt & Grime
Something as simple as a small fingerprint (on an otherwise flawless disc) is enough to diffuse the laser and cause problems with it reading properly. Of course, grime and other foreign matter is worse. It is advisable to have a quick look at the readable (bottom) side of the disc before you put it in your player, to ensure it is clean.
If you do need to clean the disc, use a CD or lens cloth (not tissue or paper towels) and wipe from the centre to the outer edge. Do not wipe in a circular motion, like you would with a vinyl LP record. Isopropyl alcohol, clear or soapy water can be used to clean a grimy disc, but never acetone or anti-static agents.
When a disc is flexed or bent too often, or excessively, it can cause the glue (which holds the layers together) to come undone. This occurs when people pry the disc from the case the wrong way (e.g. not pressing the centre release button in the case, or pulling it out from one side only). The separation starts from the centre of the disc, and will give the disc a "coffee-stain" appearance (it will look like a stain on the gold alloy layer). Unfortunately, this cannot be repaired, and will only get worse once it has started to appear.
A foil dent has the appearance of a crease, or small mark on the alloy layer, between the plastic outer layers. These usually occur when people leave discs laying around, and pressure is placed on top of the disc while it is sitting on an uneven surface, or has grit or other matter underneath it. Unfortunately, these cannot be repaired.
This refers to something that used to happen with a very early type of CD (not DVD) that was manufactured without the edges of the discs being properly sealed. Because of this, moisture was able to get into the disc and came in contact with the aluminium layer, dulling it (or giving it an appearance of rotting).
DVDs have edges that are properly sealed, and besides, they do NOT have an aluminium layer. They have a silver, gold or silver-gold alloy as their reflective layer.
I hope the above information has helped a few people. I may add further details at a later date, so check back for updates.
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