Chapter 5 Troubleshooting
112
Image not bright enough
Problems
Check Items
Reference
Setting of the brightness control knob
Adjust the brightness by rotating the brightness control
knob.
3.2.1
Aperture diaphragm is closed too far.
Open properly.
3.8
Field diaphragm is closed too far.
Open properly.
3.9
Darkness at the periphery, no viewfield seen, or uneven viewfield brightness
Problems
Check Items
Reference
Revolving nosepiece is not in click-stop position. (the
objective is not centered in the optical path).
Revolve to click-stop position (swing the objective
correctly into the optical path).
3.4.1
Dirt or dust on the lens (condenser, objective, field
lens, eyepiece), specimen
Clean the lens.
6.1
3.3.1
Image dark on one side (One side of the viewfield (up, down, right, or left) is not in focus.)
Problems
Check Items
Reference
Revolving nosepiece is not in click-stop position.
Revolve to click-stop position.
3.4.1
Specimen rises from stage surface.
Stabilize it using the holder.
―
The thickness of the sample (section) is not uniform
and has a tilt.
Prepare a sample (section) of uniform thickness.
―
Image shifts during focus (Becomes asymmetrically defocused when moving the focal point.)
Problems
Check Items
Reference
Revolving nosepiece is not in click-stop position.
Revolve to click-stop position.
3.4.1
Specimen rises from stage surface.
Stabilize it using the holder.
―
The thickness of the sample (section) is not uniform
and has a tilt.
Prepare a sample (section) of uniform thickness.
―
5.1.2 Problems in Phase Contrast Microscopy
Incomplete field of view or no field of view seen
Problems
Check Items
Reference
The phase contrast slider is not at the click position
(the annular diaphragm is not in the optical path).
Move the slider until it clicks.
2.2
4.2.2
No phase contrast image seen
Problems
Check Items
Reference
You are not using a phase contrast slider.
Mount a phase contrast slider and bring the
appropriate position into the optical path.
2.2
4.2.2
You are not using a Ph objective.
Bring a Ph objective containing a phase plate into the
optical path.
2.2
3.11
4.2.2
