12. Troubleshooting
Review the information in the table below to troubleshoot operating problems.
PROBLEM
I. Optical Section:
Bulb operates, but field of view re-
mains dark.
Field of view is obscured or not evenly
illuminated
Dirt or dust is visible in the field of view. Dirt/dust on the specimen
Image looks double
Visibility is poor.
•
Image is not poor.
•
Contrast is poor.
•
Details are indistinct.
One side of the image is unfocused
II. Mechanical Section:
Coarse focus knob is hard to turn
Focus is unstable
III. Electrical Section:
Bulb doesn't turn on.
Brightness is not enough
Light blinks
IV. Observation tube:
Field of view of one eye does not match
that of the other.
V. Microphotography:
Image edge is unfocused
Bright spots appear on the image
CAUSE
Power supply is unplugged.
Brightness is too low
Revolving nosepiece is not correctly
engaged.
Filter holder, polarizer or analyzer are
partially inserted
Dirt/dust on the eyepieces
Aperture iris diaphragm is stopped
down too far.
The field diaphragm is not well cen-
tered
Revolving nosepiece is in an incorrect
position
Aperture iris diaphragm is too closed
or too open.
Dust or dirt on lenses (objectives, eye-
pieces)
Focus is not even
Revolving nosepiece is in an incorrect
position
Specimen is not in a flat position
Tension adjustment ring is too tight
Tension adjustment ring is too loose
Power supply not connected
Brightness setting is too low
Power supply not well connected
Interpupillary distance is incorrect.
Incorrect diopter adjustment.
Your view is not accustomed to micro-
scope observation.
To a certain extent it is due to achro-
matic objectives features
Stray light entering in the microscope
through eyepieces or camera viewfin-
der
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SOLUTION
Connect
Set brightness to a proper level
Make sure that the revolving nosepiece
clicks properly into place.
Insert or remove the filter slider
Clean the specimen
Clean the eyepieces
Open aperture iris diaphragm.
Set the diaphragm according to Koe-
hler settings.
Move the nosepiece to a click stop
Adjust aperture iris diaphragm.
Clean thoroughly.
Specimen holder is not flat. Move the
specimen to a flat position.
Move the nosepiece to a click stop
Place the specimen in a flat position
on the stage
Loosen tension adjustment ring
Tighten tension adjustment ring
Check for proper connection
Adjust brightness
Check for proper connection
Adjust interpupillary distance.
Adjust diopter.
Upon looking into eyepieces, try look-
ing at overall field before concentrating
on specimen range. You may also find
helpful to look up and into distance for
a moment before looking back into mi-
croscope.
To minimize the problem, set the aper-
ture diaphragm in a proper position
Cover eyepieces and viewfinder with a
dark cloth