13 PAPER JAM"
Open up the flap at the back of the printer and look for screwed up paper - remove carefully any paper because the bit near the yellow warning label can be hot. Close back of printer.
Next withdraw the paper tray and check paper is fitted in tray ok. You might want to try turning block of paper over. Put tray back in.
If problems persist contact the Computing Facilities Group (pvdv and vbf are usually on site during the day).
For more information on paper jams see the extracts from the HP manual particularly the chapter on Solving Printer Problems