Customized Solutions; Possible Faults; Instrument Malfunctions - Leica RM 2235 User Manual

In the following table there is a list of the most common problems which can arise while
working with the instrument, along with possible causes and troubleshooting procedures.
Problem

7.1 Possible faults

1. Thick/thin sections
The sections alternate between
being thick and thin. In extreme
cases, there are no sections what-
soever.
2. Section compression
The sections are very compressed,
show folds or are squeezed togeth-
er.
3. "Stripes" in sections
For knife holder E
4. Noises during sectioning
The knife "sings" when
sectioning hard specimens. The
sections show scratches or chatter
marks.

7.2 Instrument malfunctions

1 There is no further feed motion and
thus no sectioning.
2. High blade consumption
Leica RM2235
Possible cause
• The blade is not clamped properly.
• The blade is dull.
• The pressure plate is damaged or
incorrectly adjusted.
• Clearance angle of the knife/blade
too small.
• The blade is dull.
• The specimen is too warm.
• The sectioning speed is too fast.
• There is an accumulation of paraf-
fin on the rear pressure plate of the
knife holder.
• The sectioning speed is too fast.
• The clearance angle is too wide.
• Insufficient clamping of object and/
or knife holder.
• The front end position has been
reached.
• Too great of a sectioning force was
applied.

7. Customized solutions

Corrective action
• Reclamp the blade.
• Laterally displace the knife holder
or insert a new blade.
• Insert a new pressure plate or use
a new knife holder.
• Readjust the pressure plate.
• Methodically experiment with
larger clearance angle settings
until you have found the optimum
angle.
• Use another area of the blade or a
new blade.
• Cool the specimen before section-
ing.
• Reduce the sectioning speed.
• Remove paraffin from this area on a
regular basis.
• Turn the handwheel at a slower
speed.
• Methodically reduce the clearance
angle setting until you have found
the optimum angle.
• Check all screw and clamp connec-
tions on the object holder system
and the knife holder. If necessary,
tighten the levers and screws.
• Run the specimen back by turning
the coarse driving wheel.
• Adjust the sectioning speed and/or
section thickness when trimming.
Select a smaller section thickness,
rotate the handwheel more slowly.
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