Troubleshooting:
Page 19
Optical Troubleshooting
Problem
Cause
Solution
LED light is bright, but
field of view is dark.
Field diaphragm is not large enough.
Condenser is too low.
Condenser is not centered.
Open the field diaphragm.
Adjust the condenser.
Center the condenser.
Side of the field of view
is dark or uneven.
Nosepiece is not clicked into position.
Stain or dust has accumulated on the
condenser, objective, eyepieces or light
source.
Rotate nosepiece into place.
Cleaan surfaces of condenser,
objectives, eyepieces and
light source.
Stain or dust is
observed in the field of
view.
Stain has accumulated on the specimen.
Dust or stain is on the objective or
eyepiece.
Clean the sample cover slip.
Clean the objective and
eyepieces.
Image is not clear.
No cover glass placed on the slide.
Add a cover slip to sample.
Cover glass is not the standard size.
Use cover glass thickness
0.17mm.
Cover slip is on the bottom of the slide.
Put cover glass face up.
Immersion oil has dried on objective lens.
Clean objective lens.
No oil immersion was used with 100x lens.
Use immersion oil.
Air bubble in immersion oil.
Adjust lens to remove bubble.
Incorrect type of immersion oil used.
Use Type A, non-drying oil.
Aperture is not open or set properly.
Adjust the iris diaphragm.
Condenser is not set up properly.
Adjust the condneser.
One side of field of view is
dark or the image moves
while focusing.
Specimen slide is not fixed.
Affix slide in mechanical stage.
Nosepiece is not clicked into position.
Click nosepiece into place.
Center the condenser.
Condenser is not centered properly.
Eyes fatigue quickly
during use or the right
field of view doesn’t
match with the left.
Interpupillary distance is not set properly.
Adjust interpupillary distance.
Diopter adjustment is not set properly.
Adjust the diopters.
Different eyepieces are being used in the
left and right eyetube.
Use the same eyepieces in each
eyetube. Use the Fein Optic
FPL-WF10x/22 Eyepieces.
Beam splitter is pulled out.
Push the beam splitter in.
