11. Troubleshooting
Review the information in the table below to troubleshoot operating problems.
PROBLEM
I. Optical Section:
The illumination is ON, but the field of
view is dark.
The edge of the field of view is
vignetted or the brightness is
asymmetric.
Dust and stains can be seen in the
field of view.
Poor image quality:
•
The image is not sharp
•
The contrast is not high
•
The details are not clear
One side of the image is out of focus.
II. Mechanical Section:
The focus knob is hard to turn.
The focus is unstable.
III. Electric Section:
The LED doesn't turn on.
The brightness is not enough
The light blinks
IV. Viewing tube assembly:
The field of view of the two eyes is
different
V. Microphotography and video:
The image is unfocussed
Bright patches appear on the image
CAUSE
The plug is not connected to the il-
lumination
The brightness is too low
The incident illuminator is not correctly
oriented
There are stains and dust on the
specimen
There are stains and dust on the
eyepiece
The lenses (additional lens, objective,
eyepieces) are dirt
The specimen is out of place (tilted)
The tension adjustment collar is too
tight
The tension adjustment collar is too
loose
No power supply
The brightness adjustment is low
The power cord is poorly connected
The interpupillar distance is not cor-
rect
The dioptric correction is not right
The viewing technique is not cor-
rect, and the operator is straining the
eyesight
Incorrect focussing
Stray light is entering the microscope
through the eyepieces and through
the camera viewfinder
13
SOLUTION
Connect the cable
Adjust to a proper setting
Change the angle of the incident il-
luminator
Clean the specimen
Clean the eyepiece
Throughly clean all the optical system
Place the specimen flat on the stage.
Loosen the tension adjustment collar
Tighten the tension adjustment collar
Check the power cord connection
Adjust the brightness
Check the power cord
Adjust the interpupillar distance
Adjust the dioptric correction
When look into the eyepieces, do not
stare at the specimen but look at the
whole field of view. Periodically, move
the eyes away to look at a distant ob-
ject, then back into the eyepieces
Adjusting the focus system as in the
present manual
Cover the eyepieces and the view-
finder with a dark cloth