The slide gripper lifts the entire rack instead of individual slides – what is wrong? FAQ Report A:Probably the slide sensor is dirty Clean the slide sensor (located in the small silver housing on the right hand side of the loading bay) with a soft cloth which may be moistened with some xylene. After you have finished cleaning, ensure that no cloth fibers remain on the sensor. If the problem cannot be remedied, call in a Leica service representative to check the system.