Disc Read & Tray Problems

Hey everyone, Well today i got a PS2 in which my friend gave me... After opening the disc tray i noticed it just closes right back up after a few seconds it also will not read some of my games but some work fine, I was hoping maybe someone can guide me into finding out what may be wrong, while looking at it i noticed the warranty sticker was removed and the front of the disc tray can easily be removed i'm starting to think it was modded or something, Everything else looks great on it and it looks brand new, Hopefully someone can help me find out what may be wrong with it :(

Thanks alot any ANY help would deeply be appreciated.

Well, since the front of the disc tray was removed, I bet he did the knife trick. Try doing a laser fix if you think that the laser might be broken.

Ok, I have seen a few guides i will probably wait until i gte paid seeing as i have no can of air or tools at the moment lol Hopefully that will fix it although the PS2 looks as though it has been opened before so maybe it has already been tried.

Thanks for the reply :)