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3. ELECTRICAL MAINTENANCE
The extent of electrical maintenance, by other than a qualified technician, should be bulb or fuse
replacement. BE CERTAIN TO TURN SWITCHES OFF AND REMOVE PLUG FROM POWER
SOURCE OUTLET BEFORE CHANGING BULBS.
Both top and bottom lights use the same 12 volt 10 watt tubular type bulb, National #800-400.
A. To replace top light bulb .... loosen light housing locking knob to permit removal of light housing.
This knob might be very tight, requiring careful use of pliers for removal. Making certain bulb is
cool, grasp and pull bulb from two tension clips which hold bulb in place. Holding new bulb with
tissue (to avoid getting body oil on surface of bulb), push bulb into tension clips until it slips into
position. Replace light housing and secure in place with locking knob.
B. To replace bottom light bulb .... use the “L” hex wrench to loosen set screw at side of base in
order to remove stage plate. This will expose bottom bulb, which is removed and replaced exactly
the same as top light bulb. Replace stage plate and tighten set screw.
C. Replacement of fuse
The fuse is located at rear left side of microscope base. To remove fuse from holder, insert a
6mm screwdriver blade into slot located in rear of fuse holder cap. Slightly depress and rotate
screwdriver ¼ turn in direction of arrow, release pressure on screwdriver to release the fuse. Pull
cap and fuse out of fuse holder. Insert proper fuse into fuse cap. Insert fuse cap into fuse holder.
Using screwdriver, rotate fuse cap assembly in opposite direction of arrow until guide slot
engages, depress fuse cap and rotate ¼ turn to lock into fuse holder.
TROUBLESHOOTING
PROBLEM
REASON FOR PROBLEM
SOLUTION
Light fails to operate.
Outlet inoperative.
Have qualified service technician
repair outlet.
AC power cord not connected.
Plug into outlet.
Lamp burned out.
Replace lamp.
Fuse blown.
Replace fuse.
Image does not remain in focus
Head of microscope drops from
its own weight.
Adjust tension control.
Image will not focus
Objective turret not positioned
correctly.
Turn turret until “clicks” into
index position.
Poor resolution
(image not sharp)
Objective lenses dirty.
Clean objective lenses.
Eyepiece lens dirty.
Clean eyepiece lenses.
Spots in field of view.
Eyepiece lens dirty.
Clean eyepiece lenses. ***
***Spots in field of view can also result from dirt on inside of eyepiece. It is recommended that you have
service technician clean inside of lens.
