Users press buttons.
If something stops working as expected, they will probably press every button they can see before reaching out to IT for help.
While I’m all for self-service when it comes to IT issues, we had a recent problem where a user managed to perform an NVRAM reset* on one of our HP LaserJet printers! This wipes out the serial number, page counts etc. and replaces them with XXXXXXXXXX. Unfortunately the page counts seem lost for good but to reset the serial number you need to send PJL commands directly to the printer.
This used to be done by connecting a PC to the printer via a parallel cable. You would then enter some DOS commands to copy a “PJL” file onto the printer for processing. You can also send the PJL file using the HP Firmware Update Utility/Tool but I can’t seem to find it available for download anywhere.
As I am writing this in 2013, I only have network printers and Windows 7 x64 to hand. After a lot of digging I managed to work out how to do it.