HP Original Toners

Fuser Unit

Spares

Color LaserJet 4600 Spares

The Color LaserJet 4600 was introduced in 2002; it is an older design but remains acceptably fast at 16 pages per minute. Print quality is reasonably high, running costs fairly low and most faults are emminently repairable with user-changeable parts.

The CLJ-4600 shares a lot of design features with contemporary HP colour laser printers: theCLJ-2600, CLJ-3600 and the A3 CLJ-5500 .  These printers all work the same way. Paper comes forward out of a cassette under the machine. The pickup and feed rollers push it to a registration point where attachment rollers put the paper on the ETB (Electrostatic Transfer Belt). The ETB runs up the front of the printer and it carries the paper over the four cartridges and drums, which face fowards onto it. All four cartridges run at the same time, so the image is created in a single pass. The process is much faster than the "multipass" mechanism used in HPs older 4500 and 8550 printers.

After passing the four print processes the paper is peeled away from the ETB and passes through a fuser at the top of the printer (behind the control panel) and into the face-down output tray.

The printer design is easily made duplex; that requires a reverse drive to take over just after the fuser and push the paper back in, but this time it goes down the back of the ETB, turns round sharply at the bottom and back up through the print process.

The LaserJet 4600 printer was based on the Canon LBP-2510 engine. The HP implementation seems to have been more popular. There seems to be very little English language material on the LBP-2510.?

In 2004 the design was revised to produce the CLJ-4650 models with 22 page per minute throughput and more memory. A year later the 4610N (Q7732A) was added, its a cut-down 4650 without duplex.

Many of the parts were revised or at least assigned new part numbers in the transition from the CLJ-4600 to CLJ-4610 / CLJ-4650 models.

Both fusers and transfer belts are required after tens of thousands of pages of print.

Whilst these are expensive items they are quite long lived and contribute fraction of a penny to the ownership cost of the machine. With new belt, fuser and pickup rollers the machine will print tens of thousands of pages.

Fuser

The fuser wears out because of constant contact with pages and toner which destroys its non-stick abilities and through hot-cold cycling. The fuser is the big black unit that sits in under the top cover, behind the control panel. The fuser is held in place by two blue thumbscrews - sometimes it takes a bit of wiggling to get an old fuser out of position. Fusers will typically give "Error 50" at the end of their life but sometimes shards of plastic film emerge from the top of the printer and pages that look reasonably well-formed smudge on touching.

RG5-6517	- Fuser 220 V 4600 Only; RG5-6517-110CN [code valid 2014]. A Service Manual Update note says code C9660-69003 is an exchange unit and the updated code is C9726A.
RG5-7451 Q3677A	- Fuser 220 V 4610n/4650 Only; RG5-7451-000CN part code changed to RG5-7451-130CN and then to Q3677A

220 Volt fusers are not normally available in the US and Canada

110 Volt fusers are not normally available outside the Americas, Canada and Japan. (They may be available as a special order).

Electrostatic Transfer Belt (ETB)

The Electrostatic Transfer Belt (ETB) sometimes called an Image Transfer Belt (ITB) is the large shiny black assembly visible when the front covers are open, it hinges down to replace cartridges. The belt carries pages across the toner cartridges and also acts as part of the toner transfer mechanism - the transfer rollers are behind it. The belt wears through page contact, flexing and because it's electrostatic properties decline with age. The assembly has a green handle to help lift it without touching the active surface of the belt itself (which causes problems). Two small blue clips hold it into hinged sockets behind the front cover just above the paper tray.

RG5-6484 C9724A	- ETB assembly originally listed as CLJ-4600 Only. A Service Manual Update note says code C9660-69004 is an exchange unit and the updated code is C9724A. Partsurfer says code RG5-6484-040CN can be replaced with RG5-7455-000CN which is the CLJ-4650 device.
RG5-7455 Q3675A	- According to the Service Manual this is "ETB assembly CLJ-4610n/4650. RG5-7455-000CN." HP later decided to use it in the CLJ-4600 as well. The "consumer" part number is Q3675A

Paper Pickup

The printer has two trays, a fold-down multipurpose feed tray on the front and a cassette sliding underneath. The CLJ-4600DTN and CLJ-4650DTN have an additional paper feeding unit which the printer sits on top of. The CLJ-4650 could also be equipped with a dual 500 sheet feeder in a small cabinet.

The MP tray is quite conventional with a single central pickup roller and pad. However it is a little unusual in being located at the front of the cassette! (This has been known to fool people into changing the wrong thing).

The cassette tray inserts into the base of the printer. The pickup rollers are on a spring-loaded shaft in the body of the printer and clip into place. The separation plate fits in the cassette. Worn rollers are fairly evident on examination; to confirm that a problem does lie with the rollers and not elsewhere check that the printer can print from tray 1 - that generally gets less use so will often be workable when tray 2 isn't.

There is a little kit of parts to replace all the parts likely to fail in a CLJ-4600 or CLJ-4650. Our part number is FKIT4650 and it is available here .

If paper does move but never seems to make it through to the belt and the pickup rollers have been changed the fault must lie in the paper pickup mechanism. It is certainly worth removing any dust that has accumulated, particularly on the photosensors. The assembly is available complete, both new from HP and "refurbished" - ie a pull from a working printer.

RG5-6468	- Paper pickup assembly; CLJ-4600 Only RG5-6468-000CN
RG5-7453	- Paper pickup assembly; CLJ-4610n/4650 Only RG5-7453-000CN

Laser Scanner Assemblies

Laser scanners do not fail very frequently.   Where fusers and ETB's will be required just as innevitably as cartridges the laser scanner unit might not be considered "consumable" at all. The laser itself will probably have a runtime life of about 20,000 hours before it's brightness halves, however the control circuit self-corrects for this and it is rarely an issue. The laser can last a printer life of 20 years or more. The laser assembly also contains the polygon mirror which deflects the laser across the page. Polygon mirrors spins quickly - they make the high pitched whining noise heard as a page is received. It is not surprising that they do intermittently fail. Sometimes they can be freed up with light machine oil.

There are four laser scanner assemblies, one for each coloured cartridge. The CLj-4600 and CLJ-4610 / 4650 take different types. The laser scanners are intercahngeable within the printer, which may help with diagnostics.

Fuser Drive Etc

The remaining parts are listed for completeness, they don't regularly wear out.

Information on this page is derived from the CLJ-4600 / CLJ-4650 service manual Q3668-90970 page 489 through 503.

Copyright G & J Huskinson & MindMachine Associates Ltd 2013, 2015, 2016. 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 usage patterns.