[quote name='J7.']What will have to happen to cartridges for them to stop working? How do you know if you have a pressed or burned disc? I always assumed they just burnt all discs whether retail or not.[/QUOTE]
NO retail disc, whether it's a CD, DVD, or Bluray employs recordable tech. They are all "pressed" (which is a complete misnomer, but we'll use it to avoid confusion).
[quote name='uncle5555']I was going to answer the disc question, with its mainly color, but that isn't always the best way to do so, so I won't.
However your other question is a little easier, the contacts going back is the best answer I can give you, the solid state stuff is solid (try to say that 3 times fast) and will last a very long time in properly humidified and controlled conditions, but let's face it most of us don't have places like that. So we have to deal with harsh climate and more importantly oxidation on the metal connectors on the games.
My old Neo Geo carts were oxidizing like crazy when I didn't use them for a period of 2-3 years. When I pulled out the SNES and N64 and found out my systems weren't working that well, I hunted high and lo for a SNES system cleaner, that seemed to make them both work again like new.
So yeah oxidation is the killer of carts, plain and simple, battery backup games can have the battery replaced, but that 48 min. Super Metroid Speed run is as good as dead.[/QUOTE]
There are really simple ways to avoid a lot of that corrosion. First, DE-humidify, not humidify the area that you store your games in. Keep them in a case that's relatively airtight. Then toss in one or two silica gel packets to help absorb moisture. Finally, a thin coat of dielectric grease on the contacts should keep them nice and corrosion-free for a long, LONG time.
[quote name='Nogib']Ah, no. Not even. The pits and falls (translated to ones and zeros) are pressed into plastic and a thin layer of metal is painted on only to give a laser something to reflect off of and then an additional protective plastic layer is placed on top of that.
And pressed discs are not invulnerable.
Disc rot is indeed a very real thing. Had some early movie DVDs from 2000 that flat out were no longer readable due to poor construction between the layers.[/QUOTE]
Well, if you're gonna be super technical about it, the data isn't pressed into the disc. The portion that contains the data is injection molded polycarbonate, nothing about the process involves "pressing". A lacquer is applied to the top after the metallic layer is added, not another layer of plastic. The only time that you'd find a polycarbonate sandwich is with two-sided discs.
But you are indeed correct about longevity. Like many things, build quality will have a lot to do with the lifespan of a disc. De-lamination, which allows air and moisture to make contact with the metallic layer, is the the biggest problem. It's pretty much what it sounds like; one layer pulling away from the other.