Continuous roller motor motion when CR is turned on

When I turn on my Kodak POC 140 CR, the Roller motor turns CONTINUOUSLY and I get an UNLOADING PLATE message on the Kodak QC and no further booting occurs. On the diagnostic screen the W0511 light is permanently on. The Z0505 light is also permanently on. Please how can I stop the roller from continuous motion? Also when I Open the Diagnostics screen in the Kodak QC and move the Screen Guide up and down and check the Z0505 light in the Diagnostics screen, it DOESNT turn on and off. The Z0 light on the sensor DOESNT turn on at all. Please can you help? Thanks.