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9 Troubleshooting Table
As you use your microscope, you may occasionally experience a problem.
The troubleshooting table below contains the majority of frequently encountered
problems and the possible causes.
Problem
Possible Cause
Vignetting or uneven brightness in the
field of view or field of view only partially
visible
Analyser slider in intermediate position
Compensator slider in midway position
Bertrand lens in optical path
Condenser not mounted correctly
Condenser is not centred
Condenser is set too low
Condenser top lens not fully swung in or out
Field diaphragm closed too far
Aperture diaphragm closed too far
Improper condenser objective combination
Revolving nosepiece not clicked into position
Trinocular eyepiece tube optical path selector
lever in intermediate position
Dust or dirt in the field of view
Aperture diaphragm closed too far
Condenser is set too low
Dust or dirt on specimen surface
Dust or dirt on field lens, filter,
condenser or eyepiece
Poor image (low contrast or resolution)
Uneven focus
Condenser is set too low
Aperture diaphragm closed too far
No cover glass
Too thick or thin cover glass
Immersion oil not used on immersion
procedure
Air bubbles in immersion oil
Specified immersion oil used not used
Immersion oil on dry objective
Greasy residue on eye lens
Incorrect illumination
Specimen holder not fixed securely on stage
Specimen not secured in position
Image tinged yellow
Lamp voltage is set too low
Blue filter is not being us
Focusing is not possible with high
magnification objectives
Slide is upside down
Cover glass is too thick
High magnification objectives strike the
specimen when changing over from low
to high magnification
Slide is upside down
Cover glass is too thick
Eyepiece diopter not adjusted
Insufficient parfocality of objectives
Eyepiece diopter not adjusted
No cohesion of binocular image
Magnification or field of view of left and right
eyepieces differ
Interpupillary distance not adjusted
Eyepiece diopter not adjusted
Eye strain or fatigue
Interpupillary distance not adjusted
Diopter adjustment not made
Field of view of left and right eyepiece differ
Inadequate illumination