printer-hardware-guide

paper jams: where and why

• Pull jammed paper in the direction it travels, slowly, with both hands. Pulling backwards tears it and can damage the fuser's surface.
• Open every door the display names. One scrap at a sensor keeps the error up, and a torch finds it.
• Jams at the tray, or several sheets pulled at once: the pickup roller is worn smooth, or the paper is damp. Clean the roller with a damp lint-free cloth to buy time, then replace it: it is a cheap part.
• Jams at the exit with wrinkled or curled paper: the fuser.
• Fan a new ream before loading it and never fill the tray above the mark. Paper stored in a damp room curls and sticks together.
• The paper size and type set at the printer must match what is in the tray. A mismatch stops the printer with a message nobody reads, or makes it pull from the wrong tray.
• Envelopes, labels and thick paper go through the manual feed and out of the rear door if there is one: the straight path. A label that peels off inside wraps round the fuser.

reading the page

• Print the printer's own test or demo page first, from its panel. If that page is clean, the printer is fine and the fault is in the driver or the document.
• Colour printers have four of everything. Print the supplies or quality page: it shows each colour on its own and tells you which cartridge or drum is the one.

toner, drum, fuser: what wears out

• The printer counts pages for each part and shows the remaining life on its supplies page or web interface. "Replace toner" at 0% is an estimate: pages are often fine for a while. "Replace drum" and "replace fuser" should not be ignored for long.
• A maintenance kit for an office laser printer holds the fuser, the transfer roller and the pickup rollers, due every 100,000 to 225,000 pages. After fitting it, the counter has to be reset by hand, or the message stays.
• The fuser runs at about 200 °C. Let the printer cool for half an hour before you reach in.
• Refilled or compatible toner is a legitimate saving on old printers. On new ones, weigh it against streaks, leaked toner in the machine and firmware that rejects the chip. If print quality problems started with a new cartridge, the cartridge is the first suspect.
• Keep one spare of each consumable for every printer that matters, and reorder when you fit the spare.

toner is powder: cleaning it

• Never use a household vacuum cleaner on toner. The particles pass through the filter and are blown into the room, and they can build up a static charge. Use a toner vacuum or wipe.
• Wipe spilled toner with a dry cloth or one that is barely damp, with cold water. Hot water melts toner into the fabric: clothes are shaken out, then washed cold.
• Do not touch the drum's shiny surface and do not leave it in bright light for more than a few minutes. Both show on every page afterwards.
• Before moving a laser printer further than across the room, take the toner cartridges out and carry them flat. Tipped with the cartridges in, it distributes toner everywhere.

inkjets

• Stripes or missing colours: run the nozzle check from the printer's menu, then head cleaning once or twice. Each cleaning uses a lot of ink, so stop after three and let it rest for a few hours instead.
• An inkjet that prints once a month dries out. Printing a colour page every week or two costs less than the cleanings afterwards. For rare printing, a small laser printer is the better machine.
• Printers with ink tanks instead of cartridges cost more to buy and a fraction per page. For any real volume in colour they pay for themselves quickly.
• "Ink pad full" or "service required" after years of use is the waste ink sponge. It is a service part, and on cheap models the end of the printer.

label and receipt printers

• After loading new labels the printer has to learn where one label ends: run the calibration, usually by holding the feed button at power-on or from the driver. Skipped labels and print that drifts down the label are a missing calibration.
• Set the label size in the driver to the real size, to the millimetre. The driver, not the program, decides where the print lands.
• White lines along the print direction are a dirty or dead spot on the print head. Clean the head with isopropyl alcohol and the pen that came with the printer. Never scrape it.
• Ribbon and labels must match: wax ribbon for paper labels, resin for plastic ones. A wrong pair wipes off.
• Many label printers present themselves as a generic text printer until the vendor's driver is installed, and then print pages of code. Install the right driver, and check which printer language (ZPL, EPL, ESC/POS) the software sends.

when it is not the hardware

• A printer that prints its own test page and nothing from the PC: go through the wizard for printers.
• Give every network printer a fixed address or a DHCP reservation. A printer that changed its address is the most common "it stopped printing overnight".
• Update the firmware once a year. Printers are computers on the network, and old firmware is how they become a way in.
• Change the admin password of the web interface, and switch off the protocols nobody uses.
• Before a printer or copier leaves the building for good, wipe it: it stores address books, scan destinations with passwords, and often the documents themselves on an internal disk.

The wizard: the printer does not print. Queues, spooler and drivers: printer troubleshooting cheat sheet. Toner level and page count over the network: SNMP cheat sheet.