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Time to close the case back up. Note that there are tabs along the back edge and both sides of the door, which must slide into place in order for it to fit properly, and that the lock tab on the door matches up with the same piece on the frame. The door must slide vertically back onto the computer, about 1/2 to 3/4-inch from the face piece, then slide toward the front, to latch into place. When all is lined up right, with moderate pressure the door will lock back into place as you slide it toward the face piece. There should be no gap between the door and face piece, when the door is locked in place.
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