PIONEER CLD-2070 LASER PLAYER TRAY REMOVED

Hi there , sure hope you can help me...I have a pioneer cld-2070 Laser disc player, it worked great till my little grand daughter decided it didnt need its tray anymore, when it opened she grabbed the tray and pulled it out completely.. I tried to put it back in but it just isn't lining up. It starts to go in and half way in the tray starts to drop.. instead of when it is all the way in.. I see holes in the gears, and someone said you have to line them up properly then put tray in.. i have no idea what the alignment is and i cannot find it on the internet... PLEASE someone help!!!

Thanks for the help .. I did make sure it was in the two rollers and that the lowering unit was in its tracks,, I didn't see any screw where it would stop it but I WILL LOOK CLOSER....I had it going in and down without the tray but soon as i put the tray in it moves the gears and makes it outa wack again...I s there a special way you have to align the gears ??? one gear has like an arrow or tooth missing on top and a hole on the other side and the gears in the unit has a hole like they have to be aligned..i cant seem to find a diagram on how to do this.