All Xerox documentation for that device is located here from our Downloads and Drivers page.
If you are sure that the scanners glass are very well cleaned, you will need a tech to disconnect/reconnect the flat cables from CIS sensors (at the CIS side and at the Board side)
The scanner was not used for about two months. Now we notice the first scan has a vertical black stripe, and later scans have a much lighter gray stripe (as shown in the attached image). The center of the gray stripe seems to be located at the center of the document glass (near the 4" mark). Please advise.