TM 5-6675-323-14
Table 5-4. DIRECT/GENERAL SUPPORT TROUBLESHOOTING
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1.
LIGHT INTENSITY IS NOT EQUAL FOR BOTH LIGHT GRIDS.
T e s t maximum and minimum light grid intensity. Minimum value is 500 ft
l a m b e r t s ; maximum value is 2000 ft lamberts.
Adjust dimmer circuit to equal values (paragraph 5-20.1).
2.
OPTICAL QUALITY OF IMAGE CHANGES AS STEREOSCOPE IS MOVED OVER ILLUMINATED
VIEWING STAGES.
Orient stereoscope rhomboids to minimum separation in X- and Y-directions.
If optical
quality
improves,
recollimate
optical
mount
(paragraph
FAN OPERATES.
3.
ONE OR BOTH LIGHT GRIDS DO NOT OPERATE.
Change dimmer circuit card or substitute with good card.
(a) If lamp lights, adjust dimmer circuit (paragraph 5-20.1).
(b) Replace grid lamp (paragraph 5-20.4).
4.
LIGHT GRID LIGHTS BUT INTENSITY WILL NOT CHANGE.
S t e p 1.
Check that connector to dimmer card is not reversed.
NOTE
Dimmer card connector is not keyed and may be reversed. If card is
reversed, grid lamp will operate at maximum intensity and lamp intensity
will not change.
5-40
