67
Leica CM1860/CM1860 UV
Troubleshooting
8
8.3 Possible sources of error, causes and remedies
Problem
Cause
Remedy
Frost on cryochamber walls and
microtome.
•
The cryostat is exposed to air
currents (open windows, doors,
air conditioning).
•
Eliminate cause or relocate
instrument.
•
Sliding window was open too
long at a very low cryochamber
temperature.
•
Close the sliding window
correctly.
•
Frost built up by breathing into
the cryochamber.
•
Wear a mask if necessary.
Ice formation on the bottom of
the cryochamber.
•
Shut-off valve of condensate
drain closed.
•
Open the shut-off valve, switch
off the instrument and let it
thaw and dry.
•
Draining of condensation
water of the quick freeze shelf
defrosting system obstructed.
•
Level the instrument.
Lubricate sections.
•
Specimen not cold enough.
•
Select lower temperature.
•
Knife and/or anti-roll plate not
yet cold enough – the section
melts as a result.
•
Wait until knife and/or anti-
roll plate have reached
cryochamber temperature.
Sections splinter, cracks in the
section.
•
Specimen too cold.
•
Select higher temperature.
Sections not properly flattened.
•
Static electricity/air currents.
•
Eliminate cause.
•
Specimen not cold enough.
•
Select lower temperature.
•
Large-scale specimen.
•
Trim the specimen parallel;
increase section thickness.
•
Anti-roll plate poorly
positioned.
•
Reposition anti-roll plate.
•
Anti-roll plate poorly aligned
with knife edge.
•
Align correctly.
•
Incorrect clearance angle.
•
Set the correct clearance
angle.
•
Knife dull or jagged.
•
Use a different part of the
knife.
Sections not properly flattened
despite correct temperature and
correctly aligned anti-roll plate.
•
Dirt on knife and/or anti-roll
plate.
•
Clean with dry cloth or brush.
•
Edge of anti-roll plate
damaged.
•
Replace anti-roll plate.
•
Dull knife.
•
Use a different part of the
knife.
Sections curl on anti-roll plate.
•
Anti-roll plate does not
protrude far enough beyond
the knife edge.
•
Align anti-roll plate correctly.
Scraping noise during sectioning
and specimen head return
stroke.
•
Anti-roll plate protrudes too far
beyond the knife edge and is
scraping against the specimen.
•
Align anti-roll plate correctly.