You don't need to have a disc in drive...
You don't even need a functional laser, or drive-mechanics.
I would still leave the drive connected, even thought it is not 'working' anymore, it still partially works, like a 'terminator' (some people, which know about SCSI probably know what I mean...).
Issues could occur (during init, or access), when a drive is not even connected, so better have a dead drive connected than none at all.
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux