HP Original Cartridges

(The "X" size won't fit the M601)

Reliable Remanufactured Cartridges

Transfer Roller

Maintenance Kit

The maintenance kit contains the transfer roller together with feed rollers and the fuser - which is the expensive bit.   Technicians like kits because they solve 90% of problems in one go!

… However if you have faded print it won't be the fuser or feed rollers - its the cartridge or the transfer roller. Try shaking the cartridge from side to side and make sure the contacts in the printer are clean.

HP RM1-8491 Transfer Roller for HP Laserjet Enterprise M601, M602 and M603 series Printers.

HP Part RM1-8491 Transfer Roller for HP Laserjet Enterprise M601, M602 and M603 series Printers

It appears to be identical to that for all the big mono laser printers stretching back to the LJ-4200, P4014 and to the M601 successor model the M604 - but we don't know the electical characteristics and so we certainly can't claim it is.

The transfer roller is a long black roller that uses a static charge to pull the image formed on the drum in the cartridge onto the paper. In the printer it is found immediately under the cartridge, a blue cog on one end hints that it is removable. The opposite end is conductive plastic with a wire spring connecting it to the high voltage power supply.

The roller is on a metal shaft and the material is somewhat conductive, although measurements with a multimeter often show nothing as the resistance is outside the range they measure. The roller is charged oppositely to the particles on the drum, so it is strongly attractive to them.

Transfer rollers are directly in the paper path and they will get chipped by the leading edge of the paper hitting them. They also pick up paper dust, turning somewhat grey. They can be cleaned to some extent - we use a clean paintbrush. Plain water is probably harmless to them (isopropyl generally seems to work as well, although it can de-nature some rubbers. ). As with all plastic / rubber items the material is likely to age, perhaps particularly badly because the material is intended to have a specific electrical character.

The transfer roller isn't repairable beyond cleaning.

The transfer roller may be to blame if prints have insufficient contrast. Examine the drum by doing a stop-test. If there is clearly visible print left on the drum surface after it has passed over the transfer roller then there is some fault with the roller

HP Information

HP Partsurfer shows RM1-8491-000CN:

RM1-8491-000CN Transfer roller assembly - Long black spongy roller that transfers static charge to paper

Icecat says for this transfer roller there is one short product code RM1-8491-000CN and one GTIN (EAN/UPC) code:5711045705779

The transfer roller ought to be available as a kit CE988-67903. In addition to the roller the kit would contain a blue hook for lifting the roller and a sheet of visual instructions. It would also cost a little more.

Unfortunately the Service Manual gave the part number as CE988-60793 which was a garble and doesn't exist. Connoisseurs of HP part numbers will recognise that "-67903" is a favoured ending for transfer rollers and maintenance kits but that "-60793" hardly ever happens. As a result, the kit seems to have been forgotten about - no-one in the UK stocks it, although we can get it on back order.

In case you are disappointed and would have preferred the kit we can help with some instructions. There is a carefully written up page with instructions and pictures here.

A brief summary is:

Yank the cartridge oot the machine. The transfer roller is the long black thing with a blue cog on the left hand side. Howk the shaft up with a screwdriver, observing that the teeth on the clip gan doonwards and the shaft gans in a bushin at the reet. Handle a new rowler by its blue cog so far as possible, but mind that the rowler is heavy and apt ter fall oot. Put the new rowler in the olduns place. Bin the oldun - they're nae use for owt.

Environment and Circular Economy

Old transfer rollers probably have no use beyond metal recover and even then its just ferrous. the problem is to get the plastic off, it is tightly bound. Separation is probably going to mean incineration - but it won't be popular as fuel because the energy content of the plastic will largely be used heating the metal.

It is possible to clean a transfer roller but we don't know of any way to refurbish one. There are "refurbished" rollers on eBay but they will actually just be "pulls" from working machines with no indication of expected life. Transfer rollers are more complex than just conductive foam rubber on a metal shaft. A soft, deformable roller is wanted to widen the nip-point between roller, media and OPC drum, however a smooth surface is wanted to minimise unevenness in transfer. If there are non-contact areas more then a few microns across there could be dropouts in the resulting print.

One way to reduce the environmental impact of transfer rollers would be to use a standard device - then at least there would be economies of scale both at the manufacture and recycling end. Unfortunately difference in nip width, conductivity and so forth tend to mean each printer uses a different one. There is a similar but not identical charged roller called the "PCR" in the cartridge.

As suggested above the transfer roller may well be standard at least in HP's large printers - which are a substantial part of the market. However HP keep changing the product code - so we can't be sure.

Web Research

A google Query on RM1-8491 in September 2013 gave About 7,230 results (0.25 seconds) with the first in organic search being as follows:

amazon.co.uk (ZAR Systems) £38.00, ebay.co.uk (strepx) $36.50+$12.61, tonercare.co.uk £32.50, alibaba.com no matches, extramore.en.alibaba.com contact supplier, printerworks.com refurb $15.37, fastprinters.com $28.87, partshere.com $28.55, ebay.com laserpartshq $34.95, uk-computers.co.uk £20.59, amazon.com DEC Trader $41.00, amazon.com no info, laserpros.com login for P & A, quikshiptoner.com $29.89, com-com.co.uk parts listings, printersupplies.com $29.00, cdw.com call for price, markit.eu £28.06, everprint.com refurb $ 318.08, chinaeternal.en.alibaba.com irrelevant page,txo-systems.com request quote, uk.alibaba.com no matches, trojansolutions.co.uk send form for enquiry, memory4less.com $106.44, hpoutlet.co.uk irrelevant page, store.emprgroup.co.nz $52.79, lbrty.com parts listings, store.emprgroup.com.au $40.06, mindmachine.co.uk £17.57

Prices noted are for a new item, one off, without tax. The list is as encountered. We haven't bothered with currency conversion - half of our readers are outside the UK and are more interested in dollar prices.

None of the websites seen gave any further information on the product - Wordpress supplies a little. There are one or two irrelevant listings here or P & A on request. No helpful blogs on this part. All the rest were merely vendors giving no more information than found in the HP brochure.

Supply Situation

The part is listed by a couple of distributors but they don't hold stock. We think demand for the part will be low

We should be able to provide this part when required. The price in 2013 was about £17. In July 2015 it had risen a little.

These are guidelines, our prices change with distribution lists - see the catalog. Delivery is typically 5-7 days.

Copyright G & J Huskinson & MindMachine Associates Ltd 2013, 2015. Some pictures derived from HP User and Service guides. These technical pages do not constitute an offer for sale; just our knowledge at the time of writing. See the catalog. Sales pages on this Web site use cookies to store user information. We also use Google Analytics to track site useage patterns.