17
Possible faults of the microscope and methods of their elimination
External manifestation of
the fault
Probable cause
Method of elimination
Cut or uneven illumination
The revolving nosepiece is not in fixation
position (the objective lens is not on the
microscope axis)
Tighten the revolving nosepiece and put the
objective lens into the fixed position, i.e. on
the optical axis
Any objective or eyepiece lens etc. is
contaminated
Visually inspect lenses and clean them
The condenser is not in operating position —
too low or warped
Put the condenser in the operating position
There is dust, dirt in the
field
Any lens or the stage is contaminated
Remove dirt
Poor quality of object
image (low resolution, poor
contrast)
There is no cover slip on the object, or its
thickness does not comply with the standard
Use the object with a cover slip of standard
thickness of 0.17mm
The object is put with its cover slip down
Turn the object over
Immersion oil got onto the frontal objective
lens. There is dry immersion oil on frontal
objective lens 100х ∞/0.17
Clean the immersion oil from the surfaces of
frontal objective lenses
Immersion oil was not applied on the 100x
frontal objective lens
Apply oil
There are bubbles in the immersion oil
Clean the immersion oil from the objective
lens, the object, the stage and reapply it
The aperture diaphragm of the condenser is
open or closed too much
Set the necessary diaphragm size
Object images when
observed with two eyes in
two eyepieces do not match
Eyepiece tubes of the binocular head are not
set in accordance with the observer’s eye base
Install the binocular head in accordance with
the instructions of subsection "Microscope
focusing for binocular observation"
When switching the low
magnification objective
lens to higher magnification
objective lens, the
objective lens hits the
object
The stage with the object is turned over
Install the object with the stage up
The cover slip is too thick
Use the cover slip of standard thickness
The halogen lamp is not on
after activation
The lamp is out.
The fuse blew out (safety fuse).
Replace the lamp in accordance with the
instructions of subsection "Transmitted light
illumination system"
Disconnect the microscope from the grid and
replace the fuses
The mercury-filled lamp
does not go on or went off
The power supply unit is off
Check POWER indication on the power supply
unit casing; if it is missing, disconnect from
the grid and replace safety fuses with the new
ones from the package
The mercury-filled lamp is installed wrongly
Disconnect the power supply unit from the
grid, disconnect the flashlight cord from the
unit.
Remove the flashlight (after it cooled down),
check the proper installation of the lamp
according to the instructions of subsection
"Impinging light illumination system"
The object fluorescence
brightness has reduced
greatly
The lamp failed — the bulb has become blurred Replace the lamp following the instructions of
subsection "Impinging light illumination system"
