A method of operating an imaging device having a failed or failing media-full sensor determines whether or not a controller can trust the output signal received from the media-full sensor. A reduced power or intensity level is used to test the media-full sensor and, in particular, the light source to counter the dimming of the light source that occurs due to aging and electrical noise in the system. When the output signal of a photoreceptor is at or below a threshold value, the photo-receptor is considered to have not detected the light beam from the light source and the light beam is deemed not to have been detected even though the photo-receptor may be providing a lower level output signal. Thus, an output signal of the photo-receptor is not trusted and an indication that a media storage area is not full is provided and an imaging operation is carried out.