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MAINTENANCE
WARNING: For your own safety, turn power switch off, remove plug from AC power source and remove charging cord
from microscope input before maintaining your microscope. If the power cord, recharger is worn, cut or damaged in any
way, have it replaced immediately to avoid shock or fire hazard.
1. OPTICAL MAINTENANCE
A. Do not attempt to disassemble any lens components. Consult a microscope service technician when any repairs not
covered by instructions are needed.
B. Prior to cleaning any lens surface, brush dust or lint off lens surface using a camel hairbrush. You can also use an ear
syringe or canned compressed air, such as that sold by most computer stores.
C. Do not remove eyepieces or objective lenses to clean. Clean only the outer lens surface. Breathe on lens to dampen
surface, then wipe with lens paper or tissue or use a cotton swab moistened with distilled water. Wipe lenses with a
circular motion, applying as little pressure as possible. Avoid wiping dry lens surface as lenses are scratched easily. If
excessive dirt or grease gets on lens surfaces, a small amount of Windex can be used on a cotton swab or lens tissue.
To clean objective lenses, do not remove objectives from microscope. Clean front lens element only, following same
procedure.
NOTE: Fingerprints or other matter on the front lens element of the objective lens is the single most common reason that you
will have difficulty in focusing the microscope. Before having costly servicing done, or before returning to National for
“warranty repair”, make certain to examine the front lens element with a magnifying glass or eye loupe for the presence of
such contaminants. If a microscope is returned to National for warranty repair, and it is determined that such contaminants are
the problem, this is not covered under warranty and National will submit a cost estimate for cleaning.
2. MECHANICAL MAINTENANCE
A. The rack stop screw has been pre-adjusted at the factory and should not require re-adjustment. However, if you do
attempt re-adjustment, note the following procedure.
Loosen round knurled locking nut by turning counter clockwise, and then loosen the knurled head rack stop screw. With
fine focus adjustment at mid-range, focus on standard slide until sharp image is obtained. Rotate rack stop setscrew in
clockwise direction until tight, tighten locking nut.
B. Coarse focus tension adjustment prevents the stage from drifting down from its own weight and causing the image to
move out of focus. The tension adjustment has been adjusted to appropriate tension at the factory. However, after some
period of use, tension can loosen, and the stage will “sink” from its own weight or from any slight pressure applied to the
stage. This will cause the microscope image to move out of focus, and you will need to readjust the tension control.
a. When looking at the back of microscope (facing USB port and DC recharging port) the tension adjustment wheel is
the chrome-knurled wheel immediately inside the large, coarse focusing knob on the left side of microscope.
b. Turn adjustment wheel clockwise to tighten tension and counter-clockwise to loosen tension.
c.
It is recommended that you leave the tension as loose as possible for ease of focusing, yet not so loose that it
permits the stage to drift downward from its own weight and cause the microscope to “drift” out of focus.
C. Metal parts: Use a clean, damp cloth to remove dust or dirt from metal parts, followed by a dry cloth.
3. ELECTRICAL MAINTENANCE
A. The extent of electrical maintenance, by other than a qualified technician, should be LED replacement, battery recharging
and battery replacement. Before maintenance, be sure that recharger is not connected to microscope.
B. Recharging batteries:
Plug output cord from battery charger into DC recharging socket located on back of microscope base. Your automatic
switching recharger operates on 100 to 240 volts AC 50/60 Hz. Plug charger into your AC wall outlet. Battery recharger is
also equipped with an automatic “trickle charge” feature; the red LED indicator lamp located on recharger will be
illuminated when batteries are receiving maximum charge. After batteries are charged, the red LED indicator lamp will
turn to green and charger automatically switches to “trickle charge”. The charger can be left plugged in, but for safety
reasons it is a good idea to disconnect the charger from the AC wall outlet and the output cord from recharging socket
after 12 hours. Batteries and charger may feel warm when charging, and unplugging the recharger is a safety precaution.
