you might also try placing the check on the document glass down by the 11" mark on the glass. this way you are telling the document feeder what size the original is and you check should copy onto 8.5x11. good luck!
We have ours set to autodetect. If we put a check on the glass, what exactly is it autodetecting? The machine never seems to detect dimensions less than 8.5" x 11" without a blank sheet in the back.
We received a new 7775 and we are having issues when scanning/copying checks where it would cut off about 2-3 inches in front of the check. This occurs when scanning/copying pages that is smaller than 8.5" x 11". The only way to make this work is to put a blank page behind the checks and then the scan/copy would capture the entire check. I called Xerox support and they said this is by design. Is anyone expericing this issue and what is the common fix?