Playstation 2 console Help please !!?

So I have a ps2 slim, one of the first ones that came out. Well it was recently my bday and my mom got me guitar hero 5 for the ps2. i was stoked to put it in until I saw that it wasnt reading the disk. I have World Tour as well and it sometimes works with that. So I decided to call Gamestop and see if they knew what the problem was. They said that the ps2 slims,escpecially as old as mine is, tend to loose their laser calibration.So what should I do, try to find a place that calibrates them(if there is such a place), or get a new one. Thanks for all the comments in advance.