HP RM1-7419 laser scanner for HP P4014 and M4555 Series Printers.

HP Part RM1-7419 is the laser scanner for Hewlett Packard LaserJet Enterprise M4555 printers. RM1-7419 also replaces RM1-5465 which the service manual says was used in the P4014, P4015, P4515.

The laser scanner is primarily made from black plastic with a metal lid. The assembly is roughly triangular but has a green circuit board mounted on one side which carries the semiconductor laser emitters and their control chips. Towards the apex of the triangle is the polygon mirror on it's motor spindle. and at the base is the laser shutter. When a cartridge is in place and the lid closed the shutter is open so that the laser can shine through a slit onto the cartridge drum and create the image.

The laser is quite similar to those used in CD and DVD players - possibly a bit more powerful. In this case it's a dual beam laser unit as this speeds things up. Laser beams give a small, intense spot of light tuned to a particular purpose. The laser is scanned across the page by the rotating polygon mirror. In this case the drum in the cartridge is initially charged by a roller then areas of it discharged by the laser leaving a latent image which is then shaded by the toner powder. The laser power and tuning matches the properties of the optical photo-conductor (OPC).

The laser itself rarely fails outright. Most sudden faults are likely to be the polygon mirror motor bearings. The printer should report error code 51.10.

The polygon mirror needs to rotate very rapidly and keep its position accurately. If there is the least problem in the bearings the image position will jitter. The printer detects the beam at the end of it's travel (BD signal), so it should be able to report any error. However in the past laser printers have not always succeeded in detecting this kind of instability. The lasers themselves have a feedback loop through back-diodes so inability to form a beam would be detected this way. There are some suggestions that if one laser fails alternate lines have different densities, spoiling the print quality. Printing a configuration page might help to eliminate problems such as the printer being asked for 300DPI instead of fastres 1200 and suchlike.

It might seem that anything so precise as a laser scanner would be completely unrepairable; that hasn't always been true. A frequent fault is that the polygon mirror motor becomes unstable or actually jams. Take the circlip off, lift the mirror spindle out and clean it and the shaft and it will work again. A couple of drops of machine oil will probably restore operation for a long time. Other than this repair is probably limited to cleaning the optics - mirrors and lenses inside. The laser assembly itself needs precise factory alignment and most workshops would not be able to do it. The polygon motor might be replaced but they are probably not obtainable in small quantity.

The Laser Scanner is controlled by the DC controller RM1-4582but the video data comes from the formatter and is only relayed through the DC controller. The base model formatter is CB437-69002 -and CB438-69002 is the formatter for the rest of the series.

To see RM1-7419 in context in the engineering diagrams click here.

HP Information

Sometimes we have to find parts information from HP by a combination of several methods; the service manual says one thing, partsurfer says another or omitts something. A query on RM1-5465 to partsurfer returns:

HWP-RM1-5465-000CN Laser scanner assy
RM1-5465-000CN Laser/Scanner assembly - Mounts on the support structure in the print engine frame assembly

HP's second description is true but not entirely helpful - it is true of most of the other parts in a laser printer.

Partsurfer only lists the LaserJet Enterprise M4555 MFP under the part. However the P4010 entry says

RM1-5465-000CN Laser/Scanner assembly - Mounts on the support structure in the print engine frame assembly
Part RM1-5465-000CN is no longer supplied. Please order the replacement, RM1-7419-000CN

... so confirmation of the service manual assertion that the part is RM1-5465 but it has been replaced by RM1-7419.

RM1-7419-000CN Laser scanner assembly

Partsurfer RM1-7419 only lists comptability with the M4555 MFP, however web research strongly suggests compatibility to the P4014 and the P4015, P4515 range.

Partsurfer says the part for the LJ Enterprise M601 is RM1-8406. Partsurfer says of that:

RM1-8406-000CN Laser/scanner assembly

... and lists the LaserJet Enterprise 600 M601N, M601DN ... M602, M603 etc.

The Enterprise M4555 seems to be the pinnacle of the P4515 series rather than a member of the M601 series - although there are overlaps they don't include the laser scanner.

RM1-5465-000CN = EAN/UPC 5704327456995, Product Views = 32, Category = Print Heads
RM1-7419-000CN = EAN/UPC 5711045250521, Product Views = 47, Category = Printing Supplies

The P4014 series laser scanner has definitely been called RM1-5465 and then RM1-7419. (So RM1-5465-000CN and RM1-7419-000CN as well. Web research often suggests it has also been RM1-4511. Printertechs say also RM1-8074. Amazon has an ASIN of B005LFNG2I.

The RM1-7419-000CN fits all the P4014, P4015 and P4515 printers and the less common M4555 MFP.

Web Research

A Google query on the code RM1-7419gave About 105,000 results and a list of vendors:

Amazon (ZAR Systems) £467.00, eBay (pcbaby) US $350.00, Lambda-tek £243.20, eBay (LaserXperts - strepx ) £19.32 -£29.50, eBay (action-guy) £18.34 - US $28.01, Morecomputers £297.09 with free delivery but no stock, Printerworks £404.20 new £77.83 refurb, Brokenprinter $119, sparepartswarehouse new $399.29 refurb $328.31, databazaar $161.91, Amazon refurbished from $155.8, Laserpros no price, 360tech $145, Techworldparts used $34.99, Printertechs $175, Txo-systems RFQ, Laptops2desktops $199.00, Icecat no price, Bargainseekr $199.00, Techpartswarehouse RFQ, Yoursourceglobal refurb $145.00, Partsnow login for price, usaprinterguy $199.00 sale $155.88, Memory4less $229.63 discounted to $195.18, IDNS no price, Dectrader $333.00, Rapid-tech no price, Print4everexpress $0, Zauba (broker), Mynordicbroker (broken link).

Prices noted are for a new item without tax by deafult. However these items are frequently sold "refurbished" and that isn't always made clear - anything sold for less that £240 has to be refurbished and some of those for much higher prices were too. The list is as encountered. We haven't bothered with currency conversion because of our readers are often outside the UK and more interested in dollar prices.

Printertechs were the only site that offered any information beyond what was discoverable from HP Partsurfer and distribution lists.

Fitting a new laser assembly is not difficult but might be a job for an experienced technician. The top and sides have to come off the printer so the laser itself and its cables are accessible. The laser unit may need alignment in the factory but as supplied it is pre-aligned to the chassis. The laser assembly is held by a few screws and a new one just drops into place, screws down and the wires need attaching. There is no setup procedure.

Supply Situation

There will probably be one global manufacturer for laser scanners like HP RM1-5465 / RM1-7419. Compatible manufacturers presumably won't attempt to make something quite complex like this and with a small market profile. Asian clone manufacturers seem absent from the list above. In July 2013 these parts are available from two sources - HP new and other vendors offering refurbished.

A new laser scanner is going to be about £250 in the UK because that is just a bit above HP's trade price. We have reservations about the quality of compatible parts but a challenge to HP's price for a new item might be welcome. A laser-scanner is markedly less complicated than a CD player. The price of new laser scanner units has always been high - sufficiently to act as a disincentive to repair. However these were fairly expensive printers in the £550 to £1500 range and replacing one with a LaserJet Enterprise 600 M601dn will still cost about £590. If you are quite clear that the fault relates to the laser assembly because error code 51.10 or similar is displayed then a new RM1-7419 laser assembly might be warranted.

Our research suggested an enormous range of refurb prices from £19 to £467 and no real consensus. We doubt "refurbished" means anything more than "used". We wouldn't normally open a used item up to clean the optics or bearings unless we tested it extensively afterwards. Testing the brightness of the dual beam laser might be possible but the easy way to do that is to verify the machine print quality. There is not a great deal of refurbishing that makes sense - for instance if the optics are dirty then the item might clean up but it probably shouldn't be sold. For "refurbished" read "used".

The part is listed as new by a couple of distributors in the UK under RM1-7419 but they don't hold stock. RM1-5465 was not mentioned in the distributor lists, neither was RM1-4511 or RM1-8074. We think demand for the part will be very low.

We can provide these parts when required. The new price is about £250 in August 2013 which is largely because of HP's high price. We can try to source the part "refurbed" - we think brokers will provide one by dismantling a printer for about £70 or so but that remains to be seen.

Price and availability are just guidelines, our prices change with distribution lists - see the catalog. Stock numbers indicate there is not much call for the part. As yet we have found no further information beyond people offering the part for sale; very little on it curing faults outside .