Does the xray fit the glass. make sure it does not cover the clear strip, just in front of lamp home poition, that is for self calibration. As you do not give a model, does the transparency unit close as a lid, or slide in, again make sure xray film is not obstucting any part. Try a scan with out the xray in place, if scans, something to do with the xray position
SD
April 2012