Make sure to keep your printer up to date by downloading drivers and patches from the manufacturer's site. Most manufacturers provide driver updates for their units which include patches that add fonts or fix incompatibilities.
If debris is the primary cause of failures, toner is the primary cause of debris. All toner cartridges release a small amount of toner powder into the machine. This is why it's important to clean the machine when you change the cartridge.
Printer not working? The printer memory could be full and not getting prints or the prints may be stuck in the print queue. Turn-off the printer, wait a few seconds and turn it back on.