Leica RM2125 User Manual

The Leica RM2125

Microtome

Online Troubleshooting Guide

Leica RM2125 Troubleshooting Guide

Table of Contents

Problem Page

1. Thick and thin sections 1-2

2. Compressed sections (sections are extremely compressed, wrinkled or jammed together) 3-4

3. Chatter 5-6

4. Scratches or splits in sections 7

5. No specimen advance (no section produced) 8

6. Drifting of handwheel 9

7. Specimen is picked up in the return stroke of the specimen arm 10

8. Sections sticking to pressure plate 11

9. Unable to retract specimen 12

10. Microtome makes "clunking noise" when sectioning 13

Leica RM2125 Troubleshooting Guide

Problem

1. Thick and thin sections

a) Partial sections
b) Shorter sections in ribbon
c) Section thickness varies from one section to another
d) Skipping sections
e) Varied thickness in one individual section

Cause(s) / Corrective Action

I) The clearance angle is too small.

a) Systematically try several clearance angle adjustments until the optimum angle is found. For the RM2100 series use 2.5 degrees (Disposable).

II) Insufficient specimen clamping.

– Orientation head
– Cassette clamp

b)

Check if all the levers are locked and the screws are tightened on the specimen. Retighten the levers and screws, if necessary.

c) If the clamp lever can be tightened at more than a 60 degree turn, adjustment is needed.
d) Schedule a service call for the adjustment of the specimen head clamp lever.
e) Check 4 screws that hold the orientation head to the advance arm.
f) On the cassette clamp, check the 4 screws that hold the cassette clamp to the orientation head.
g) Check for movement of the cassette while in the holder. If movement exists, it may be caused by: weak/broken springs, wax buildup, or lack of grease

A service call is required to replace spring and properly grease. If there is wax build up, instruct customer to clean with a sparing amount of Xylene.

III) Locking levers are not well lubricated or cleaned, which causes them to be not completely fastened or stuck in a non-locked position.

h) Remove all locking levers, clean off all paraffin and debris, then apply a sparing amount of the provided Leica lubricant.

Lubricate only with recommended KuBer Topas Grease, which can be ordered through Leica. Part Number: 14033624744

IV) Leaf spring is worn.

i) Replace leaf spring. Part number: 14050229557
j) If the new leaf spring does not solve the problem, then replace the locking lever. A service call is required for this.

V) Dull knife/blade.

Use a different part of the cutting edge or use a new knife/blade.

k)

1

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Leica RM2125 Troubleshooting Guide

Problem

1. Thick and thin sections

a) Partial sections
b) Shorter sections in ribbon
c) Section thickness varies from one section to another
d) Skipping sections
e) Varied thickness in one individual section

(continued)

Cause(s) / Corrective Action

VI) Backlash in specimen advance system.

l) Test for backlash by trying to rotate the object head clockwise and counter clockwise. If there is play in the

system, schedule a service call for the internal adjustments of the specimen advance system.

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2

Leica RM2125 Troubleshooting Guide

Problem

2. Compressed sections (sections are extremely compressed,
wrinkled or jammed together)

a) Compressed
b) Wrinkled
c) Jammed

Cause(s) / Corrective Action

I) Dull knife/blade.

a) Use a different part of the cutting edge or use a new knife/blade.

II) Blade/knife is gummed up with paraffin

b)

Clean knife with a swab moistened with Xylene. Stroke the swab in an upward motion away from the blade edge, not down on the blade edge.

III) Specimen is too warm.

c) Pre-cool the specimen on a cold plate.
d) Cool the specimen in iced water or with an icecube.
e) Use freeze spray immediately before sectioning. (NOTE: Some labs prohibit the use of this spray, please advise.)

IV) Clearance angle is too big.

f) Clearance angle adjustment: Systematically decrease the clearance angle until the optimum adjustment is obtained.
g) Check the leaf spring screw for washers and tightness.

V) Leaf spring is worn.

h) Replace the leaf spring. Part number: 14050229557
i) If the new leaf spring does not solve the problem, then replace the locking lever. A service call is required for this.
j) Check angle of pressure plate facet to see if correct. Refer to User Manual, page 29-30.

VI) Paraffin buildup on the back of the pressure plate.

k) Clean knife with a swab moistened with Xylene. Stroke the swab in an upward motion away from the blade edge, not down on the blade edge.

VII) Knife blade is not parallel with pressure plate.

3

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