This might seem like a strange question to ask (or one that has an obvious
answer), but...

I bought a lot of second-hand DVD-ROM drives. All are of varying vintage,
and all of them work perfectly except this one Toshiba SD-M1212 drive.
Optically and electrically it is fine. I can load a disc, set everything up
manually, and put the unit back together far enough that a CD or DVD will
play perfectly after applying power.

The problem is that the tray mechanism appears to be out of time. By itself
that shouldn't be a big problem. I've repaired optical drives with tray
mechanisms that had jumped time many times in the past.

I cannot get the tray mechanism back in time on this drive. It doesn't help
matters that I can't see or get at the gears when I'm putting the tray back
on the track after timing everything correctly. (Or at least trying to time
things correctly.) There is no damage to gear teeth, and the loading motor
(which is connected by a gear instead of a belt in this drive) has plenty of
torque.

I'd like to try and fix it just to keep something else out of the landfill.
I'm just wondering if this particular drive has a special procedure or
action that needs to be taken to get it going again.

William