HP LaserJet Pro 400 M401dn: wired automatic duplex with a touchscreen review

The HP LaserJet Pro 400 M401dn is an earlier monochrome printer for an office that shares documents over Ethernet and regularly prints both sides. It combines Gigabit wired networking, automatic duplex and 300 sheets of standard input. The boundary is equally important: this is a print-only model with no built-in Wi-Fi radio or scanning equipment.

The surviving US HP page maps this exact dn model to CF278A#BGJ and marks it discontinued. Its original specification sheet supplies the detailed model column. An older printer can be useful in a maintained setup, but the name alone cannot establish the condition, driver compatibility or supplies in a particular offered unit.

Automatic duplex is the reason to choose dn over n

The original comparison explicitly lists automatic two-sided printing for the M401dn. The supported-paper table confirms Letter, Legal and A4 through the duplexer. Those are positively documented sizes, rather than an assumption that every printable stock can travel through the same two-sided path. Select the appropriate paper size and type, and keep specialty media within its separate restrictions.

HP declares a maximum 35 one-sided Letter pages per minute. The A4 figure is 33 pages per minute; it should not be relabeled as Letter speed. Neither is an automatic-duplex throughput claim. The manufacturer’s ISO/IEC 24734 qualification excludes the first test set and warns that the system, driver and document can affect results. No new timed result is claimed here.

A wired printer can serve a suitable AirPrint network

The dn interfaces include a USB device connection and 10/100/1000 Ethernet. Ethernet supports ordinary shared printing when the network and computer software are configured correctly. The separate front USB facility accepts supported PDF and JPEG files from a flash drive; it is not the USB socket used to connect the printer to a computer.

Apple AirPrint is explicitly listed for the dn in HP’s original model column. A phone or tablet on a suitable shared network can therefore use the supported network arrangement even though the printer itself is wired. The guide notes a possible firmware upgrade requirement. The direct USB desktop arrangement does not borrow AirPrint from the Ethernet setup.

The original specification assigns built-in wireless networking to M401dw, not M401dn. A requirement to connect the printer itself to the office Wi-Fi therefore points to another exact model. Historical web applications and cloud-printing claims also need separate current checks; their names are not a guarantee that an old remote service remains available.

Paper input and the room it actually needs

The included 50-sheet Tray 1 and 250-sheet Tray 2 make a 300-sheet plain-paper configuration. Each tray accepts Letter, Legal and A4 in the original paper table. The separately purchased 500-sheet feeder can expand an equipped unit, but is excluded from standard capacity here. Ask what hardware is actually present rather than comparing a maximum expanded figure with another printer’s included input.

Legal paper requires extending Tray 2 behind the body by approximately 2.75 inches. HP lists the unit body as 14.35 by 14.49 by 10.67 inches, with a 24.2-pound weight including the print cartridge. Opening the multipurpose feed, extending paper support and raising the touchscreen needs more room. A closed-body fit is only the start of checking a shelf.

Envelopes belong in Tray 1 with the documented settings and guides. The supported-media table excludes envelopes from the automatic duplex route. Occasional address printing and ordinary two-sided reports can coexist as separate tasks, without implying that envelopes should run through the duplexer.

Its color screen is not color output or a scanner

The M401dn’s 3.5-inch color touchscreen is an operating control. Printing remains monochrome. The hardware description includes no scanner, automatic document feeder, standalone copy function or fax assembly. Generic scan wording in a family publication cannot supply those missing components.

HP recommends 750–3,000 pages per month and separately specifies a maximum duty of 50,000. Use the recommendation for a continuing office workload. The original package includes an HP 80A cartridge with an approximate 2,700-page yield; replacement CF280A and CF280X declarations are about 2,700 and 6,900 pages under ISO/IEC 19752. Actual yield varies, and these figures do not determine a current cost per page.

Before choosing an older example, verify the US 110–127V label, configuration, present driver and a real duplex network job. The M401dn is a sensible configuration to investigate for wired black-document sharing. A wireless or multifunction model is the better direction when the job explicitly requires those additional capabilities.