15
VII Troubleshooting Table
The troubleshooting table below contains the most frequently encountered problems and their possible
causes.
Optical and Operating Problems
Problem
Possible Cause
Vignetting or uneven brightness
in the field of view or field of view
only partially visible
Lamp not installed properly
Filter slider in intermediate position
Phase slider not in click-stop position
Incorrect condenser mounting
Condenser is set too low
Condenser is not centered
Field diaphragm closed too far
Aperture diaphragm closed too far
Revolving nosepiece not clicked
into position
Optical path selector lever in
intermediate position
Dust or dirt in field of view
Aperture diaphragm closed too far
Field of view diaphragm image not
focused on specimen surface
Dust or dirt on specimen’s surface
Image quality:
No image under phase contrast
or details cannot be viewed
Brightfield objective being used
Phase annular diaphragm not in
optical path
Phase annular diaphragm and
objective phase symbol do not match
Slider annular ring image has
moved away from the objective
phase plate image
Field of view diaphragm image not
focused on specimen surface
Thickness of specimen holder is
outside the compensating range
of objective
Eye strain or fatigue
Interpupillary distance not adjusted
Diopter adjustment not made
Inadequate illumination
Field of view of left and right eyepiece differ
Electrical
Lamp does not light
Power supply not plugged in
Lamp not installed
Lamp burnt out
– 100hrs Average Life
Inadequate brightness
Specified lamp not being used
Lamp blows out immediately
Specified lamp not being used
Lamp flickers
Connectors are not securely connected
Lamp near end of service life
Lamp not securely plugged into socket
Never attempt either of the following actions, since doing so will damage
the focusing mechanism:
o
Rotate the left and right knob while holding the other.
o
Turning the coarse and fine focus knobs further than their limit.
