EOTech CNVD-T3 Clip-On Night Vision Device - Thermal 3 - Manual (Page 55)

3-3
c. Display is on but no image is present.
(1) Open the objective lens cover.
(2) Focus on an object in the distance.
(3) Adjust display brightness per section 2.9.
(4) Place the unit in auto-gain mode per paragraph
2.10.1.
d. Objective focus ring may be difficult to turn after
exposure to extreme temperatures.
(1) Rotate the objective focus ring to a point
approximately halfway through its full range of
travel.
(2) Use a #1 Phillip’s head screwdriver to loosen
(do not remove) the rear purge screw shown in
Figure 3-1. This step should require only 3-4
complete revolutions.
Figure 3-1 Rear Purge Screw
Purge Screw