Selenium is a nonmetallic element used in the photography trade. A selenium meter uses selenium to measure the exposure of a photograph being taken with a camera. Located just above the optical lens, the meter is very sensitive, and any dirt or dust on it can interfere with its ability to perform. You can repair a selenium meter in your camera as long as you are very careful and handle the meter with great care.
Take off the film advance latch by pulling it up and away from the camera.
Open the back of the camera and push the spindle of the rewind up and out of the case. The rewind is on the far left side of the camera when you are looking at it from behind.
Remove the tiny screws holding the top cover of the camera in place. You will have one at each end of the cover and possibly one along the front.
Take out the two small screws holding the meter in place on top of the camera. Gently lift the meter out of the camera and set it on a clean surface.
Brush any dust or dirt from the meter using the lens brush. You should also clean the area where the meter was.
Rub off any persistent marks with a cotton swab and a very small amount of solvent.
Replace the meter inside the camera and insert the screws into the camera to hold it in place.
Put the top cover back on and insert the screws. Put the rewind and advance controls back on as well.
Take a picture of how the meter is set in the camera before you remove it so you can put it back in correctly.
Never touch the lens or screens of the meter with your fingers, as the oil on your hand can destroy the meter.