19
8 POSSIBLE TROUBLES AND TROUBLES-SHOOTING
Troubles
Probable reason
Troubles-Shooting
No luminance of the
screen after switching
the device on
The batteries are instal-
led in the wrong order.
The batteries are
discharged.
The objective lens is
covered.
Install the batteries right
order.
Change the batteries.
Remove the cover.
Have the device repaired
Week
screen
luminance
The batteries are
discharged.
The objective lens is
covered.
Change the batteries.
Remove the cover.
Not sharp image
The objective lens or
eyepiece are not
focused.
Focus the objective lens
and adjust the eyepiece.
No luminance of the
screen in the presence
of the bright source
of light in the field of
view
The protective scheme
operates.
Get the bright light source
out of the field of view.
