From UW-Math Wiki
What to do if your job does not print
NOTE: if the red light is lit on the start button, there is a problem (usually no paper)
a. Check the status of your print job with one of these commands lpq -P N (where N is the floor you sent the job to) lpstat -t b. Check that there is paper in the tray. If not, get a ream of paper from the copy center and put it into the top tray. If you are uncertain about how to do this, ask the computer staff in 507 for help.
c. It may be that your job was formatted for a different paper size (usually A4). In this case, press the printer button on the left. You will see a dialog box saying that the job calls for a non-standard page size. Select one of the trays (usually tray 1 or 2) to try to force it to print on lettersize paper.
d. If there is a paper jam, please ask Henry in 507 to fix it and try sending your job to another floor.
e. If all else fails cancel your job. For example, if lpstat -t shows your job as
then type cancel 5-27 to cancel the job.
f. If the printer doesn't to appear enabled, type cupsenable 4, if your printer was on the 4th floor, subbing in the appropriate number if on a different floor.