PS1/2 Why do some PSX discs have trouble being read, while looking flawless (no scratches, etc)?

[duskfall]

So I got a few squaresoft PS1 RPGs to better study Japanese. This quite baffling thing happened to BOTH games.
The first disc (these are multi disc games) will either not be read, OR will not play properly (it will be slowed down, music, CG cutscenes, everything will be a little slower).
While the physical disc itself is a black label one and is in (at least visually) impeccable condition.
Why is this happening? I'm not looking for a solution as I've already found one (try another disc), just curious if anyone has a better guess on why this is happening. And it's always on the first disc that this happens.
My two guesses:
1) Some kind of elaborate anti-region unlocking prevention measure by Sony (but then why would disc 2 play?)
2) They used the first disc so much that it somehow got ruined but not in a way that is visually seen.
For the sake of sharing information, the two games that I've had this issue with are FFVII and FFVIII (Japanese titles). FFVII disc one would not be read, and FFVIII disc 1 would play, but everything in the game would be slowed down (lol)

 

[Ligeia]

CDs and DVDs are just prone to deteriorate over the years.

 

[SylverReZ]

Likely your PS1's laser is starting to wear out. I'd suggest either replacing or calibrate the laser using the repair guide. https://alex-free.github.io/unofficial-ps1-cd-drive-service-manual/

 

[duskfall]

Likely your PS1's laser is starting to wear out. I'd suggest either replacing or calibrate the laser using the repair guide. https://alex-free.github.io/unofficial-ps1-cd-drive-service-manual/

But the other disks work fine (Disc 2, Disc 3). So I'm not willing to think it's the laser. Using a PS3 btw.

 

[Ryab]

So I got a few squaresoft PS1 RPGs to better study Japanese. This quite baffling thing happened to BOTH games.
The first disc (these are multi disc games) will either not be read, OR will not play properly (it will be slowed down, music, CG cutscenes, everything will be a little slower).
While the physical disc itself is a black label one and is in (at least visually) impeccable condition.
Why is this happening? I'm not looking for a solution as I've already found one (try another disc), just curious if anyone has a better guess on why this is happening. And it's always on the first disc that this happens.
My two guesses:
1) Some kind of elaborate anti-region unlocking prevention measure by Sony (but then why would disc 2 play?)
2) They used the first disc so much that it somehow got ruined but not in a way that is visually seen.
For the sake of sharing information, the two games that I've had this issue with are FFVII and FFVIII (Japanese titles). FFVII disc one would not be read, and FFVIII disc 1 would play, but everything in the game would be slowed down (lol)

Well first of all I suggest ripping all of your discs in case they fail as by this point they have likely started to show minor signs. But past that I suggest cleaning the laser on the system. Also different games read the discs in different ways so some games are slower than others.

 

[duskfall]

I looked for disc rot and found none. Maybe this disc got scratched a lot and got rebuffed. I bought these used from amazon .

 

[SylverReZ]

Well first of all I suggest ripping all of your discs in case they fail as by this point they have likely started to show minor signs. But past that I suggest cleaning the laser on the system. Also different games read the discs in different ways so some games are slower than others.

Easy way to tell that they are starting to deteriorate, is by shining a bright light on the disc. If you see any mold growing or holes, then that's one way.