Night Optics TG-7 Thermal Goggle/Binocular (30Hz) - Manual (Page 15)

Chapter 7. Operator Preventive Maintenance Checks and Troubleshooting (cont’d)
7-2. Following is a list of possible discrepancies, their possible causes, and suggested operator
procedures to correct them:
Discrepancy Probable Cause(s) Corrective Action
Unit will not turn on Discharged batteries.
Replace and discard old
batteries.
Unit will not turn on
Batteries installed
backwards. Reinstall with proper
orientation.
No display through eyepiece
Objective lens-cap still
on.
Remove.
Partial scene
Mud or debris on
objective lens. Remove/clean per cleaning
procedure.
Foggy or fuzzy picture Dirty or greasy eyepiece.
Clean with wet & dry lens
paper. Recommend using
Demist Shield.
Scene out of focus
Incorrect lens/diopter
setting(s). Refocus objective, then
diopter settings.
Undefined scene Moisture in system.
Return to maintenance facility
for nitrogen purging.
Recommend using Demist
Shield.
Optics hard to turn, or grinding Dirty threads. Evacuate to maintenance.