Hit it with a box of cereal.

The only thing I can think of is that there is probably a deep scratch on the dics cause the other ones work.

well, i looked into it, and as it turns out, Substance has a Duel-Layer set up...so i adjusted my lense in the PS2...Now i've got "Disk read error" every time i put it in...i think it's dirty...

Any advise on how to clean it?

Clean Dr MAX.

If you've already taken the PS2 apart, you can grab some rubbing alcohol and a Q-Tip and VERY GENTLY rub the alcohol soaked q-tip along the lens in a circle pattern. Remember to dry it off with the other end of the Q-Tip.

i had similar problems with my first 2 ps2's. they were the old models. cold be the lens assebly itself, as sometimes it gets warped, and it will play some discs, but not others. if at all possible get a slimline or a ps3. my slimline has neevr given me any problems at all.

Are those old Metal Gear games good? I was thinking about trying to maybe buy one or rent em.

Metal Gear Solid (the original) IMO is the best in the series, at least in terms of the older consoles. Snake Eater was great, but I still say MGS was the best. Guns of the Patriots though? Shiiiiiiiit...

The best thing I can tell you take it to a best buy cause they can fix it just tell them your probelm and they'll do their best to fix it. Same thing happend to me games it wouldn't read the disk gave it to best buy in a couple of days the cleaned it out and told me my lazer was burnt so they fixed it.
Do that if it's more than one game that's not working but if it's just that one game then there is something wrong with the disk.

That used to happen to me a long time ago . I remember being so pissed that after a week , all my games don't read , meaning I wasn't able to play MK Deception online for a while . I went to try to find a place to repair it , however they wanted it the same price as how much the PS2 cost now . I was like WTF and instead I bought the slim and have to say its way better , and I had it for years , and had no problems . But yea , dual layered cds seem to cause to burn out the reader and could mess with the white circle looking thing inside the ps2 and I heard somewhere you have to adjust it in some way , but I don't know how . I still have my broken ps2 reader today and don't know what to do with it , I have a feeling later on in life I will mod it . Rely on your readers above and go to best buy and repair it , if its same price as new ps2 and you can get the slim ps2 , get the slim ps2 .

It means it's time to get XBox 360.

jk, I had that problem with my PS2, just put in a game that works then after couple mins put in the game that not working, it might work (not all the time)