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6
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Troubleshooting Guide
1. Optical system
TROUBLE CAUSE
SOLUTION
The edge of the
field of view is dark
or the brightness is
not uniform
The nosepiece is not in the located position (objective and
light path not coaxial)
Locate the nosepiece
properly where it clicks
The image of filament is not centered
Center the filament
A lens (the objective, condenser, eyepiece or collector) is
dirty.
Clean it thoroughly
Find dust and stain
in the field of view
There are stains on the lens
（
including condenser,
objective, eyepiece and collector
）
Clean it up
There are stains on the specimen
Clean it up
The position of the condenser is too low
Loosen the condenser’s
locking bolt, adjust the
condenser to the right
position
The image is
defocused ( low
resolution \
contrast)
There is no cover slip on the specimen
Add coverslip
The cover slip is too thick or too thin
Use the standard
coverslip ( 0.17mm )
The specimen is placed inversely
Reversal it back
There was oil on the dry objective(easily happened in
40X objective)
Clean it up
There are stains on the lens
（
including condenser,
objective, eyepiece and collector
）
Clean it up
didn’t use oil for the oil objective
Use immerse oil
There was bleb in the oil
Eliminate the bleb
Use a unsuitable oil
Change to the specified
one
The size of the aperture diaphragm is too big
Minify it
There are stains on the incident lens of the binocular tube
Clean it up
The size of the aperture diaphragm is too small
Open it up
The position of the condenser is too low
Adjust the position
One side of the
image is dark
The condenser is not in the center of the field of view\the
condenser inclines
Install the condenser
again and adjust the
center carefully by
centering the bolt
The nosepiece is not in the right position
Turning it until it reach
the “clicked” position
The specimen is floating
Fix it
The specimen slips on the stage
Fix it
