Troubleshooting - National DC-128 Instructions Manual

C. 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.
Note that your microscope can be used during recharging. Simply turn "on/off" switch on back of microscope base to "on"
position and proceed as follows. In case of equipment malfunction, see "Troubleshooting" procedure.
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. Remove four rubber feet that secure cover plate to base and remove plate. Battery
case is mounted on inside of base. Using small Phillips screwdriver, carefully remove Phillips screw that holds battery
case together. Slide lid of case straight back 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 of battery case, replace Phillips screw, replace base plate and four rubber feet.
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 directions in "3.b" above.
D. 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 illuminator field lens housing, use hex wrench supplied with your microscope to loosen hex screw on side of
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 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.
Batteries fully discharged and will
not recharge.
Rheostat control not turned far
enough.
Light switch in off position.
LED "bulb" burned out.
Slide upside down.
Slide cover slip too thick.
Objective lenses dirty.
Eyepiece lens dirty.
Too much light, light intensity not
adjusted properly.
Too much light, iris diaphragm
Not adjusted properly.
Too much light when using 4x and
10x objective lenses, swing out filter
not in optical path.
Eyepiece or condenser lens dirty.
Specimen slide dirty.
7
SOLUTION
Recharge batteries.
Replace batteries or
charger.
Turn rheostat to increase
intensity.
Turn light switch on.
Replace LED "bulb".
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 light intensity.
Adjust iris diaphragm.
Place swing in filter into optical path.
Clean lens. ***
Clean slide.
replace
light