Is the optical roller in the cartridge toner being replaced?
In most cases, the original optical roller is constructed in a way that it can be used for another cycles. This means that only the toner powder is being refilled, and other worn-out parts are replaced in case of need. After that second cycle, replacing the optical roller is necessary (rebuild). “long life” high quality rollers, which allow several consecutive refills, thus largely improving economical quality.
