Today, I visited this Lexmark X792 in EC4 central London. The problem with this particular printer was that there was a major paper jam deep inside the printer. One commonly occuring reason for this fault is the build up of paper dust on the internals of the printer. The dust, if left without being cleared, will cause significant damage to the printer, especially if the machine is heavily used. We recommend requesting a qualified printer engineer to do this, as this process involves dissasembling the printer completely and cleaning the fuser unit which, if done incorrectly, could lead to much worse and more permenant damage. Unfortunately, on this occasion the build up of paper and dust had caused irrepairable damage to the fuser and it had to be replaced. Once this delicate process had been done the printer was back up and running again. One final piece of advice for high volume users who have critical printing needs, I recommend having a spare fuser unit and transfer belt onsite to avoid unwanted printer down time in your workplace.