18. Troubleshooting
Review the information in the table below to troubleshoot operating problems.
PROBLEM
I. Optical Section:
The illumination is on, but the field of
view is dark.
The edge of the field of view is vignett-
ed or the brightness is asymmetric.
Dust and stains can be seen in the field
of view.
Image looks double
Poor image quality:
•
The image is not sharp
•
The contrast is not high
•
The details are not clear
•
The phase contrast is low.
One side of the image is out of focus.
II. Mechanical Section:
The coarse focus knob is hard to turn.
The focus is unstable.
CAUSE
The plug of the LED holder is not con-
nected to the illumination set
The brightness is too low
Too many colour filters have been
stacked
Fluorescence filter selector is not in a
click stop
Fluorescence shutter is closed
Fluorescence filter is not suitable for
the specimen
The nosepiece is not in the correct po-
sition
The color filter is partially inserted
The phase contrast slider is not in the
proper position
There are stains and dust on the spec-
imen
There are stains and dust on the eye-
piece
The size of the aperture diaphragm is
too small
The nosepiece is not in the center of
the light path
The aperture diaphragm in the view of
field is opened too much or too little
The lenses (condenser, objective, eye-
pieces are culture dish) is dirty
In phase contrast observation, the bot-
tom thickness of the sample is more
than 1.2mm
A bright field objective is used for
phase contrast observation
The condenser ring is not aligned with
the objective phase ring
The light ring and/or the phase con-
trast ring is not centered
The objective used is not compatible
with the phase ring
The phase contrast depends on the
sample position
The nosepiece is not in the center of
the light path
The specimen is out of place (tilted)
The tension adjustment collar is too
tight
The tension adjustment collar is too
loose
Page 47
SOLUTION
Connect them
Adjust to a proper setting
Minimize the number of the filters
Move the selector to a click stop
Open the shutter
Use a suitable filter
Turn the nosepiece to a click stop
Insert the filter to full depth
Move the slider to a click stop
Clean the specimen
Clean the eyepiece
Open the aperture diaphragm
Turn the nosepiece to a click stop
Adjust the aperture diaphragm
Thoroughly clean all the optical system
Use a sample holder whose bottom
thickness is 1,2mm
Switch to a phase contrast objective
Adjust the condenser ring to match the
objective phase ring
Adjust the bolts to center them
Please use a compatible objective
The sample holder is not flat. Move the
sample around until a compatible area
is found.
Turn the nosepiece to a click stop
Place the specimen flat on the stage
Loosen the tension adjustment collar
Tighten the tension adjustment collar