It is not possible to completely make the drive inoperable, you can go into the system settings and add a password that won't let any DVD's play without being entered, but the games themselves use DVD information for FMV playback and need to use the DVD player in the PS2 for gameplay.
Brian Mckelvey
June 2006
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix games consoles.