PS2 not reading PSX cds?

Ok I am so sorry if this doesn't belong inside this forum, but I couldn't find another forum with a more fitting description so here we go.

Yesterday I FINALLY from nowhere found FFVII in my closest video game store and to a good price too, so of course I couldn't do anything else than just give after for the impulse. Guy behind the desk let me take a look at the discs before I decided to purchase it too, and man not a single scratch or finger print on ANY of them (the FFVIII demo either.) It's like did the previous owner of the game even play it once?
Well. Awesome.
Well not so awesome, for some reason my PS2 decides to just make horrific noises when I put the CD in, like real KACHU KACHA KACHAN CHHHHHH noises. The FFVII demo and disc 2 and 3 works fine though. And I've been looking for any kind of clue why it's just disc 1 who's not working, and..it's..so clean. I've had this problem with the PS version of FFVI, but it works now. And the PS makes these sounds when I start playing FFVIII too, but it's fine in just some seconds really. NO problems at all with PS2 games. What could be wrong? I'm starting to wonder if my PS2 hates PSX games, but still doesn't make any sense why the FFVIII demo and the other discs worked, though they're just as clean as the first disc. God sorry for the wall of text, and again I apologize if this is the wrong forum. :>

Here ;)

OK! I made it work. Stupid enough of me there were this little string of dust attached that i didn't notice and I removed that and bam it's working again.
But I still wonder why my PS2 still sometimes throw a fit when it comes to reading PSX discs.

Another thing people may want to be wary of with playing PSX games on a PS2, is that PSX games won't play (for me at least) whenever I'm using a component connection to my TV. Make sure you KEEP the original RCA cables that come with the PS2. However, I can't remember exactly if the games themselves don't work, or there just isn't any picture on the TV.

You can also use the S cables to hook up the ps to the tv for a sharper image.

My PS2 didn't want to play PS1 games either. I didn't know the laser flips depending on the disc you're playing. I opened it up and used a can of air in it and it started working just fine. Maybe you should try that.

Oh, thanks for replying guys, Guardian XIII that sounds like it would be a good idea, considering FFVIII is still acting up on me. : )

Now I'm having another problem with FFVII and I just don't understand what has happened. I started it up (disc 3, which I've been playing on and it's been fine) but now it's just acting up all of a sudden. I reset it once, and after that, the Highwind doesn't work. You can enter it, fly around with it, but it doesn't turn to the left or right or go down or up or anything. You can enter the cockpit and then go again, but for example it can't go down to smash into Ultimate Weapon or Northern Cavern for example, the game just doesn't react. And battles. The battle gauges load right up and the active character's name is blinking, but well would you look at that, no battle menu! So the only way I can win battles now is to hope for the enemies to attack Cloud so that he counters but really I don't think that's an effective strategy to beat Sephiroth. . ....not that I can get to him because of the malfunctioning Highwind. I guess I could take the CD and get someone to take a look at it just wondering if someone knows what could've happened...

I've never heard of something like this occuring before. Don't take your disc in if it doesn't have any scratches, cuz I doubt it'll be that. It's most likely the PS2. The problem with mine was there was too much dust in it. If you used the can of air then it's probably something else. My brother smokes in his room and the smoke built up on the inside caking it with resin and destroying any chance of playing a game glitch free. Do you smoke?

Other than that I'd say that it could be something got knocked loose (but don't quote me on that cuz I really wouldn't have a clue). Maybe you should try testing more than just two games on it and see if it is the PS2 or just the disc.

Yeah i figured as much. Well of course I've tried with more games, and they..work just fine really. It's just the PSX games acting up from time to time, so probably it's the console. Thanks for the feedback! I'll get a friend over later I hope we can fix it with your suggestions. Guess we could start with to check if it works properly on another PS2 or something.