Troubleshooting Tips
Common Brightfield Microscopy Problems
| Issue | Possible Cause |
|---|---|
| No light from light source | Power switch off |
| Power cord improperly connected or not plugged in | |
| Problem with power supply | |
| Blown fuse | |
| Faulty bulb/defective bulb contacts | |
| No light seen through microscope objectives | Light source covered |
| Field diaphragm closed | |
| Aperture/iris/condenser diaphragm closed | |
| Objective not in the light path | |
| Field only partially illuminated | Condenser off-center |
| Aperture/iris/condenser diaphragm closed too much for the objective being used | |
| Field diaphragm partially closed | |
| Objective only partly in light path | |
| Electrical cord lying in the field | |
| For Nikon 50i: neutral density filter partly pushed in | |
| For Nikon 50i: optical path switching lever (for camera) in incorrect position |
| Issue | Possible Cause |
|---|---|
| Weak illumination | Light adjustment knob/rheostat/lamp voltage turned too low |
| Light source covered or burning out | |
| Aperture/iris/condenser diaphragm closed too much for the objective being used | |
| Condenser too low or not centered | |
| Using oil immersion lens with no oil | |
| For Nikon 50i: neutral density filter engaged | |
| For Nikon 50i: preset switch has been engaged (only required for camera use) | |
| Uneven illumination | Light source not centered |
| Condenser not centered | |
| Field of view too bright | Light adjustment knob set too high |
| Image cannot be focused | Slide very dirty/greasy |
| Slide up-side down | |
| All objectives dirty | |
| Dirty eyepieces | |
| Diopter adjustment improperly set | |
| Vibration on the bench | |
| Image very yellow | Blue filter missing |
| Light adjustment knob set too low |