AS-4000 User’s Guide Maintenance Performing a Self-diagnosis The self-diagnosis feature checks if the color measurement unit is operating properly and measuring colors correctly. Self-diagnosis takes a few minutes. A message is displayed if the white calibration tile or the spectrum sensor module needs to be cleaned after the self-diagnosis. A From the Maintenance menu, press Check Print Quality - Self-diagnosis (color measurement unit) . Self-diagnosis starts automatically. B Check the results of self-diagnosis. If the self-diagnosis is completed successfully, color measurement can be performed correctly. Press OK to return to the Check Print Quality screen. 93