a. Loosen the rack stop screw (Fig. 3) with the 2mm key.
b. For the 18 series: With the fine focus adjustment (20) at mid-range, focus on specimen
slide, using only the coarse focus knob (19), firstly with the 4X objective, then with the
10X.
c. For the 28 series. Focus on specimen slide using only the coarse focus knob, firstly with
the 4X objective, then with the 10X.
d. Rotate the rack stop screw until tight enough to prevent the stage (8) rising further.
Troubleshooting
ELECTRICAL PROBLEMS
PROBLEM CAUSE
SOLUTION
The bulb does not work
Bulb burned out.
Wrong bulb.
Replace bulb.
Replace by the correct bulb.
The bulb flickers
The bulb is not inserted correctly in
the socket.
Insert it correctly.
IMAGE QUALITY
PROBLEM CAUSE
SOLUTION
No image.
Nosepiece badly positioned.
Image too bright.
Turn, until it clicks into position.
Reduce light intensity.
Poor resolution.
Objective lens dirty.
Eyepiece lens dirty.
Specimen slide upside down.
Cover slip on specimen slides wrong
thickness.
Light too bright.
Condenser dirty.
Clean objective.
Clean eyepiece.
Place slide with slip facing up.
Use 0.17mm thick cover slip.
Reduce light intensity or adjust
diaphragm aperture.
Clean condenser.
Spots in field of view.
Dirty eyepiece.
Dirty slide.
Dirty condenser.
Clean eyepiece.
Clean slide.
Clean condenser.
Uneven illumination of field Nosepiece not properly positioned.
Diaphragm not properly positioned.
Turn until clicks into position.
Adjust accordingly.
MECHANICAL PROBLEMS
PROBLEM CAUSE
SOLUTION
Does not stay in focus.
The stage drops down.
Adjust coarse focus tension.
Does not stay in focus.
The rack stop of the ascending
movement of the stage is badly
adjusted.
Readjust rack stop screw.
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