Help me diagnose this ps2.

[colburn2769]

Ok, i got this broken ps2 off ebay. Got it in today, hooked it up,

Plays ps1 games fine

Plays ps2 cd rom based games fine

Plays audio cds fine

The only thing i have found wrong with it so far is that it will not play dvd rom ps2 games. I get a disc read error. It kinda sounds like the laser is struggling to read the disc. Im thinkin a good cleaning of the lens will fix it up. Might even need a new one. Am i right or is it somethin else. Thanks for any advice or help