BOT/MICRO/ZOO 5364

TROUBLE-SHOOTING

1)  Condenser image does not expand and contract concentrically

a)   Condenser aperture misaligned.  Re-align and center filament image.

b)   Condenser lens not stigmated.  Adjust stigmation of lens using "C-2 Stigm" wheels, using desaturated filament image.  Adjust for greatest clarity of shadow detail.

2)  Image cannot be stigmated with objective stigmator

a)   Objective aperture not centered.  Center objective aperture.

b)   Objective aperture contaminated.  If no position of the objective aperture reduces astigmatism, the hole may be contaminated.  Check and update "aperture map" on user message board.

c)   Condenser aperture misaligned or condenser not stigmated.  Check centering and alignment.

d)   Problems persist.  Call EML personnel.

3)  Image is distorted or cannot be focused.

a)   Specimen holder contaminated.  On low mag, image distortion is evident near the limits of the grid.  Contact EML personnel to clean and replace.

b)   Grid or specimen contaminated.  Distortion evident near grid bar or contamination.  Avoid distorted areas and use cleaner grids in the future.

c)   Very poorly stigmated.  See stigmation section.

d)   Microscope grossly out of alignment.  Call EML personnel.

4)  Beam too dim

a)   check filament saturation and position

1)   if obtaining a very distorted darkened filament image, the filament may be grossly undersaturated.  This is likely to occur when accelerating voltage has been changed.

2)   check gun alignment, which may also be changed with changes in accelerating voltage.

b)   condenser aperture is too small.  Replace with larger aperture (apertures are largest near the open position).  Center aperture.

c)   gun bias too low.  Adjust gun bias upward, re-center filament and resaturate

5)  No beam

a)   if this occurs just after inserting specimen, check to make sure:

1)   specimen is fully inserted into the microscope column (two stops).

2)   specimen grid bar or other obstruction is not present.  Turn down magnification to check this.  Position specimen to center of specimen traverse (500,500).

3)   check steps below, if no success.

b)   objective, intermediate or condenser aperture obscuring beam.  Remove apertures to check this.  Center apertures.

c)   magnification too high.  Reduce magnification.  If any beam visible, go to "Beam too dim" above.

d)   filament blown.  Check beam current milliampmeter.  If zero, call EML personnel to change filament.

6)  Image drift

a)   Specimen unstable.  Either continue to irradiate specimen until movement stops or remove specimen and carbon coat using vacuum evaporator.  (Or cut thicker sections; thick sections tend to drift less.)

b)   Whole image unstable.  (Drift seems to occur for grid bars as well as specimen.)  Microscope specimen holder is grossly contaminated.  Call EML personnel to clean and replace.

7)  Photographic START button not lit

a)   No film in holder.

1)   Camera exhausted.  Empty camera and replace with new film.

2)   Camera just changed, film not yet advanced into position.  Turn off room lights, press "MANUAL" button (to engage), press "START", wait several seconds, press "STOP", press "MANUAL" button (to release).  Start light should be lit.

b)   Camera jammed.  Call EML personnel.

8)  Mechanical problems

a)   Microscope does not pump down after changing plates or opening column.

1)   Fast leak (pump louder than usual).  Re-leak scope, check and reseat all seals, and try again.  Call EML personnel, if this doesn't work on the second try.

2)   Slow leak.  Usually caused by poorly dessicated film: call EML personnel to replace phosphorus pentoxide if fused.  Well-dessicated film usually needs only 10 minutes to reach operational vacuum.

b)   Gross problem in valving or operation.  Attempt to valve scope to a "safe" position, call EML personnel immediately.

c)   Any other mechanical problem:  Call EML personnel!  Most problems are trivial and can be fixed immediately; however, we can evaluate whether or not a service call may be required.  (Problems aggravated by the user can result in user-billable service calls at $60/hr, plus transportation, time in transit, food and expenses.  Almost all problems are covered by service contract.)

9)  Problems with microscope persist

After checking rational trouble-shooting steps, call EML personnel!  (Don't be shy.  This is a $100,000 scope; we spend over $8,000 per year for an all expenses paid service contract.  Try to get your (and our) money's worth out of it!)