Troubleshooting - National 210 Instruction Manual

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.
You may operate the microscope light even while it is being recharged. Simply flip light switch to "on" position and
continue using microscope while the recharger is fully engaged.
b. Replacing batteries:
Your microscope includes 3 rechargeable AA nickel metal hydride batteries. These may be recharged up to 500
times, but if you observe that a recharge is providing significantly less than 40 hours of operation. It is probably
time to replace to batteries.
IMPORTANT WARNING: DO NOT USE REGULAR ALKALINE BATTERIES IN THIS MICROSCOPE. ANY
ATTEMPT TO RECHARGE ALKALINE TYPE BATTERIES COULD RESULT IN BATTERIES EXPLODING.
Gently lay microscope on its side or back. Observe small door in center of microscope bottom base. Loosen
slotted screw on door and open. Battery case is mounted on inside of door. Using small Phillips screwdriver,
carefully remove Phillips screw that holds battery case together. Slide lid of case straight out to remove and
expose batteries. Remove all 3 batteries and replace with new rechargeable AA nickel metal hydride batteries,
making certain to insert with correct polarity according to markings on battery holder. Replace lid, close and
secure door.
Follow instructions on new battery packaging to determine if they are already charged, or if they should be charged
before initial use. If recharging is required, follow instructions in "3.a" above.
c. Replacing LED element:
An LED "bulb" will last up to 50,000 hours, so you don't have to do this exercise very often.
To open the illuminators field lens housing, use 0.9mm "L" type hex key wrench supplied with your microscope.
Loosen hex screws on lens housing. Remove lens housing to expose LED "bulb". Remove bulb by grasping the
plastic base of bulb and gently pulling straight up. Insert new LED "bulb", replace lens housing and tighten hex
screw to secure lens housing in place.

TROUBLESHOOTING

PROBLEM
Light fails to operate.
Image does not remain in focus
Image will not focus
Poor resolution
(image not sharp)
Spots in field of view.
***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.
REASON FOR PROBLEM
Batteries fully discharged.
Rheostat control not turned far
enough.
Light switch in 'off' position.
LED "bulb" burned out.
Fuse Blown
Stage of microscope drops from
its own weight.
Rack stop not set at proper
position.
Slide upside down.
Slide cover slip too thick.
Objective lenses dirty.
Eyepiece lens dirty.
Too much light.
Eyepiece or condenser lens dirty.
Specimen slide dirty.
7
SOLUTION
Recharge batteries.
Turn rheostat to increase light
intensity.
Turn light switch on.
Replace LED "bulb".
Replace Fuse
Adjust tension control.
Adjust rack stop.
Place slide on stage with cover
slip up.
Use 0.17mm thick cover slip
(No.1 cover slip)
Clean objective lenses.
Clean eyepiece lenses.
Adjust diaphragm.
Clean lens. ***
Clean slide.