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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.
9.1 Optical
Problem
Possible Cause
Vignetting or uneven brightness in the field
of view or field of view only partially visible
Lamp not installed properly
Lamp not centered
Diffuser is in intermediate position
Condenser not mounted correctly
Condenser is not centered
Condenser is set too low
Condenser top lens not fully swung in/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)
Condenser is set too low
Aperture diaphragm closed too far
No cover glass
Too thick or thin cover glass
Immersion oil not used with oil immersion lens
Air bubbles in immersion oil
Specified immersion oil not used
Immersion oil on dry objective
Greasy residue on lens
Incorrect illumination
