LASER PROBLEMS WITH Ps2 DVD-Help please

[DUDEKHAN]

I've got the first version of Ps2 and it quit playing Cds pretty much right out of the box. DVDs worked fine though. I bumped the CD laser output up a little and it loads ALL CDs fine now. Then it quit loading DVDs so I bumped that up a little bit and it was loading them fine HOWEVER it still wouldn't load DVD movies and hasn't for awhile. I've been playing Medal of Honor and it was loading every time. I got the new Ps2 demo disc. It loaded and worked fine but would not load any demo games, just clicking. I bumped the DVD output up a little more and the demo games loaded fine. When I put Medal of Honor back in it wouldn't load and now no DVD games will load. Have I lost the sweet-spot on the adjustment? I tried adjusting some more but no matter where I stop it won't work and I've been pretty careful about marking my spot. The laser is putting off red light still so I don't think it's fried. Also how far will that screw turn-I've been careful not to force it-it seems like it will only turn about 90 degrees or so. Any help will be appreciated.