4
PROBLEM
POSSIBLE CAUSE
Dust or dirt in field of view.
Dust or dirt on objective, illuminator or
eyepiece.
Poor image (low contrast or resolution)
Iris diaphragm is not set properly.
No cover glass in place.
Too thick or thin cover glass being used.
Greasy residue on eyepiece or lens.
Illumination is set too low.
Uneven Focus
Stage has drifted. Adjust coarse tension
adjustment so stage will not fall out of field of
view.
Specimen is not secured in position on stage.
Specimen is tilted on the stage.
Focusing is not possible with high magnification
objective lens.
Slide is upside down.
Cover glass is too thick.
High magnification objective (100x) strikes
the specimen when changing from low to high
magnification.
Slide is upside down.
Cover glass is too thick.
Rack stop needs to be adjusted.
Eye strain or fatigue.
Illumination needs to be adjusted with iris
diaphragm and/or rheostat control.
TROUBLESHOOTING: Optical
TROUBLESHOOTING: Electrical
PROBLEM
POSSIBLE CAUSE
Lamp does not turn on and light up.
Power cord not plugged in or batteries need
replacing.
Light is burned out.
Fuse is burned out.
Inadequate brightness.
Rheostat knob needs adjustment.
Lamp blows out immediately.
Incorrect bulb being used.
Lamp flickers.
Connector wires are not secured.
Lamp near end of life.
Lamp not securely plugged into socket.
