If an image does not come up on screen consider the following:

The field iris or condenser iris is closed. Open it up.

The phase contrast or darkfield condenser is dropped down vertically too far under the specimen. Rotate it up under the slide.

The dedicated darkfield condenser is too far off center. Take it off and look at the underside of the condenser while you physically move the centering screws and eyeball it to center. Put it back on and go through the adjustment routine.

The objective lens turret is not set in place. Move to click into indent position.

The objective iris is closed. Open it.

The prism knob on the side of the trinocular head is not pulled out. Pull it out.

The camera power is not plugged in to operating AC.

The camera video output is not connected to the monitor video input.

The monitor video/line input button or menu selection is not set properly.

Phase contrast appears weak, three dimensional, or faded:

First check to make sure the turret condenser is “set” into the appropriate indent. PH1 for 20x objective, PH2 for a 40x, PH3 for 100x,

Adjust the phase ring / annulus to center it with the objective. Use your centering telescope or technician trick if not available. See video tutorials.

Raise the condenser so the top condenser glass appears as if it is touching the bottom of the slide. If not and it is raised up as far as it will go, make sure the condenser is seated all the way “up” in its holder.

Darkfield image is not available when turning the turret condenser to DF:

Raise the condenser so the top condenser glass appears as if it is touching the bottom of the slide. If not and it is raised up as far as it will go, make sure the condenser is seated all the way “up” in its holder.

Fuzzy dots or dust particles appear in TV image with standard def camera:

Dust is a bugger to get off—and this is an understatement. In many cases dust particles may show up faintly and sometimes this will change as the zoom is changed. If the dust is not blaring and a complete distraction, consider this a normal consequence considering all of the optical elements in the zoom path and the level of adjustment and magnification we are desiring with our systems.

Biomedx returns to the manufacturers many video cameras and zoom systems which we consider unacceptable. Within the video camera industry, so many “dead” pixels are allowed to appear on any given video image to meet acceptable levels. We find this too lenient and are more stringent, and further, we apply the same level of consideration to dust oriented artifacts on video optics. This generally is not a consideration in darkfield mode but with zoom systems in phase contrast it is a different ballgame. Basically the center 30% of an image should be clean, with only a few dust “spots” off-center acceptable.  

If you should take your standard definition camera off of your zoom system or take your lenses apart and then experience particles that were not there in the past, you can attempt to clean this off. Generally any dust showing up on the image will be dust on the glass covering the CCD chip of the video camera or on the zoom module top lens. To know which it is, loosen the zoom coupler and the camera while you have an image on the monitor, then while holding the camera still, rotate the zoom coupler and watch the video image. If the dust rotates, the dust is on the zoom lens, usually closest to the CCD chip. If the dust particle does not move, the dust is on the CCD chip cover glass.

First, attempt to blow off the offending particle with an air can. (NOTE: NEVER place the air nozzle on a lens and then pull the trigger as propellant can be discharge and coat the lens which will be a bigger problem. Lightly pull the air trigger first and then move the nozzle to the lens.) In darkfield mode you will never notice dust in the video path, but this is not so with phase contrast because of the gray background.

BIG NOTE: wiping any lens in the video path on a high powered microscope is fraught with peril. It is VERY EASY to make a small problem worse, and it can take quite a while of playing around, wiping the lens, blowing with air, vacuuming and such to try and get spots out of the final image. With that said, you can attempt to get particles of dust cleaned up by wiping the offending lens and CCD cover lightly with lint free lens tissue. If that did not work, put one or two drop of lens cleaning solution (from a camera store or you can try basic glass cleaner like “Sparkle” glass gleaner which is very good) on your tissue and clean lens. Humidity helps to keep down static electricity which can  seem to charge the lens and attract dust.


If you are unsuccessful at resolving the following conditions, contact Biomedx  for a Return Material Authorization (RMA).  Do  not attempt to repair the light source. Tampering with the electronics will void the warranty.

Fan operates, but low light output.

Check the lamp to ensure that it  is fully seated.  See “Installing the lamp" section.

Check to  make sure the fiber optic component is fully seated.

Check the lamp.  A partial short in  the lamp may cause low or intermittent output.

Check the intensity setting.

Over time, lamps wear out and decrease in brightness. As they near the end of their life they can decrease in output dramatically.

Fan operates, but output is intermittent (every few minutes, lamp turns off and turns on).

The light source is  running too hot. A thermal cutoff protects the circuitry from heat failure. Check air intakes and exhaust areas for dust or dirt accumulation.  Make sure the unit is installed on a flat hard surface and there is a minimum of 4 inches space behind the unit’s fan. If not, move the light source to another location.  NEVER enclose the light source without adequate ventilation.

Fan operates, but the light turns briefly on and then off.

1.   The lamp may have a faulty filament. Turn the intensity control knob to maximum setting to test the lamp.

2.   If the lamp fails,  change the lamp following the instructions in  this manual.

  1. Examine the lamp socket assembly for damage and continuity.

Fan does not operate, light is dim or non-existent.

Make sure to use the correct model for the power available. Running a  240V unit in 120/100 volt conditions will stop the fan and dim the lamp.

Fan operates, light is not on.

Replace the lamp.

Fan does not operate, light is on.

Return to Biomedx.

Fan and lamp are not working.

Make sure the power cord is inserted completely into the IEC connector and also into the correct power source. Check the power cord for damage.  Check the fuse.

Fiber input is burning.

This could occur if you were using the Fiberoptic Lightsource with another mfg cable. Check the fiber type.  It may be plastic and susceptible to burning, even with the use of a standard IR heat filter. All Biomedx fiber optic light guides are made with glass fibers.

Ask your supplier about the epoxy used to manufacture the fiber optic input. Some epoxy types cannot withstand the high temperatures developed in  the light source.

Check the lamp type.  Replace the lamp with Biomedx approved types EKE or EJA. (Use an  IR filter if possible. Fiberoptic inputs damaged  by use of non-approved lamp will void the fiber warranty.

Troubleshooting Microscope Issues