Large format scanners are very technologically advanced equipment. Like a high performance race car, they need to be tuned and adjusted correctly to perform as advertised.
The most common large format scanner problems are: not recognizing paper size correctly, lines in scans, or colors are totally unacceptable. These can be corrected by cleaning the scanner glass, re-rejuvenate the rollers, and running the calibration applications. This is also good time to upgrade firmware, drivers, & application software.