Just discovered that two on my unlocked trays were stuck. Above instructions, in particular method B worked a treat to release them.
However freeing up the mechanism so a Button press translates to a slide action of the lock mechanism was not so obvious to fix. In the unlocked position A, neither effected tray buttons were pressable even though they worked fine when I set the unit up about a month ago.
I found that cycling the security lock tab several times was the answer. This process requires removing HDD from tray to access the lock tab. Cycling the main release lever did not fix things on either of my effected drives as I suspect the problem is related to the relationship between the button, slider and security lock.
