The specimen is floating on the
stage.
Reinforce it reliably.
5.
The image moved
when focusing.
The nosepiece is not in the located
position
Turn it into the required
position
6.
The image takes
the yellow
slightly.
Not use the color filter.
Use the blue filter.
The opening of Aperture
diaphragm is too small
Properly make it larger
Condenser position is too low
Adjust the position
7.
The bright
degree is not
enough
Stains on the lens (Condenser,
Objective, Eyepiece)
Wipe up
14