Sony DCR-TRV120 Operating Instructions Manual page 119

Maintenance information and precautions
Removing dust from inside the viewfinder
(1) 1Remove the screw with a screwdriver (not supplied). 2Then, while holding
the RELEASE knob up, 3turn the eyecup in a counterclockwise direction and
pull it out.
(2) Clean the surface with a commercially available blower for a still camera.
(3) Turn the eyecup in a clockwise direction, then replace the screw.
Caution
Do not remove any other screws. You may remove only the screw to remove the
eyecup.
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