HP LaserJet Enterprise M601, M602, M603.

HP are the worlds largest printer brand and particularly strong in office laser printers.

The HP LaserJet Enterprise M601, M602 and M603 are key products intended for offices where paperwork is critical. The printers are very similar, the M601N prints at 43 pages per minute, M602 -50ppm and M603 -60ppm. The M4555 is a 52ppm multifunction copier-printer based on the same print-engine.

This page overviews the printer mechanism using a cross-section diagram. These printers are highly maintainable, parts likely to wear out can be changed with nothing more than latches and clips.

The M601 series is strongly based on the heritage of the LaserJet 4200, 4350, and P4015.   Anyone used to working on those printers will find the principles and some of the parts familiar.

General Principles

Paper normally travels in an "S" shaped path outlined in dark blue. Paper normally comes from the tray under the printer where it is picked up and driven towards the registration station by the cluster of three rollers shown in pink.

An alternative route is from the drop-down multipurpose tray on the front of the printer. It is shown folded up, the rollers are shown coloured lilac. In practice rollers are blue, white, grey and black.

Paper is straightened and momentarily held in the registration station then released to pass between the photosensitive drum and transfer roller where it picks up the image. The cartridge holding the drum and toner is shown coloured green here, the whole print cartridge is user-changeable and disposed of or recycled when the toner runs out.

The laser scanner (shown blue) has a semiconductor laser which is rapidly modulated with the data to be scanned onto the page. This points through a mirror into the cartridge and onto the photosensitive drum.

Paper then passes into the fuser (coloured orange). The fuser sleeve unit heats the material passes under it to the point where toner softens and adheres to the paper, the pressure roller drives the toner into the material. The resulting documents are neat and robust.

Paper can simply exit onto a rear tray but normally heads up into the tray on the printer top.

Duplex models of the printer have an extra mechanism that reverse the paper as it gets to the intermediate delivery roller and pushes it down the back and under the fuser, along the underside of the printer and back up into the registration station. The page is now the other way up, making double sided print possible.

Consumables:

The only consumeable is a cartridge. There are two versions:

HP 90A (CE390A) Black toner cartridge with 10,000 page yield for the M601, M602, M603 and the M4555.

HP 90X (CE390X) Black toner cartridge with 24,000 page yield for the M601, M602, M603 and the M4555.

These cartridges cost as much as some printers! On the other hand they last more than 10 times as long as the cartridges for low cost printers.

Around three-quarters of the problems likely with a printer can be solved by changing the cartridge. Paper misfeeds and fuser failures may need spares.

Spares:

Paper Jam

Paper jam's sometimes called "misfeeds" are often readily detectable because the printer will stop and a piece of paper has to be removed. Very often the paper is just a bit displaced from the tray, sometimes there doesn't appear to be any paper trapped, the printer just goes to Error 13 which is Paper Jam.

Paper jam problems are usually solved by changing the relevant pickup and feed roller set. It is possible to diagnose problems more precisely, the printer has a set of paper detectors (a few are higlighted in yellow) which are supposed to move after the rollers operate and if they don't software stops the printer and shows Error 13.

Fuser Faults

Fuser problems can often be detected and reported by the printer as a 50.1 error or similar. The fuser sleeve unit contains a powerful heater which helps fix the image created in toner powder onto the page. If the heater fails the printer can detect the problem and report an error.

The toner image would stick to the fuser-sleeve except that it is made from a teflon-like material on a metal foil. After one or two hundred thousand pages the foil's non stick properties degrate and the metal backing may degenerate. The printer can't detect this but the user can - some of the toner won't stick to the page properly and bits of fuser material come out the back of the machine and even into the paper tray. The fuser then needs replacing.

CF065A Maintenance kit for HP M601, M602 and M603. Contains a fuser, transfer roller and a set of pickup and feed rollers. If the fuser in one of these printers has failed or the printer says it is worn out then rollers probably need replacing. The printer is likely to show Error 13.

RM1-8396 Fuser alone. Fusers sometimes fail prematurely due to accidents like labels getting stuck, sharp objects passing through or power surges damaging the heater. The printer will show Error 50.

FKITP4014 Paper Feed Repair Kit. Paper feed rollers sometimes wear more rapidly than expected due to differences in paper weight and quality, or to users adjusting paper feed guides to tightly.

CB506-67905 Paper Feed Repair Kit for Tray 1 - the mulitpurpose drop-down tray often used for envelopes or letterhead.

CB506-67904 Paper Feed Repair Kit for Tray 2 and 3,4,5 or 6 if they are fitted. These cassette drawer(s) slide into the printer base.

Service:

Options and Accessories:

No Options: this is a basic simple printer.