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LaserJet 4600-4610-4650 Fuser Installation

Updated: Nov 20, 2018

Technical Service Bulletins

Installation Instructions:

  1. Open the top cover of the printer and locate the fuser unit.

  2. Loosen the two blue knobs securing the fuser by turning them counter-clockwise.

  3. Use your thumbs and pointer fingers to grab the fuser at the front andback of the far left and right side fuser covers. There are treads in the plastic there so that you can get a better grip.

  4. Lift the fuser straight up and remove it from the printer.

  5. Hold the replacement fuser in the same way you lifted/removed the original fuser from the printer. The blue knobs and green levers should face your chest.

  6. Place the fuser into the printer, aligning the blue knobs and main connector in their proper position. Press down firmly on the tops of the left and right fuser covers to engage the fuser's connector. If you feel any solid resistance, STOP! The fuser and printer may sustain irreparable damage if forced into place when improperly aligned. Lift the fuser up and reset it into position. It may be necessary to slightly wiggle or pivot the fuser into place.

  7. Secure the fuser by turning the blue knobs clockwise until the fuser is locked in place. If the blue knobs are hard to turn, turn them counter- clockwise a few times, then start turning clockwise. If the printer/fuser makes a grinding or moaning noise after installing the fuser, remove it and reinstall it, ensuring that it is seated properly.

The 4600 and 4610/4650 fusers look almost identical but are not interchangeable. They can easily be misidentified, leading to problems upon installation/replacement. The printer will display a 50.4 FUSER ERROR in any instance of the wrong fuser being installed in the printer.

Helpful Resources

If the printer reports a 50.4 FUSER ERROR, verify that you are installing a 4600 fuser into a 4600 printer or a 4610/4650 fuser into a 4610/4650 printer.

To identify which model fuser you have, inspect the main drive gear on the left side of the fuser. The 4600 fuser has a white gear and the 4610/4650 fuser has a black gear.

****** If the fuser's sleeve does not spin when you manually turn the gear, please do not assume that the fuser will not run in the printer. At room temperature, the grease applied inside the sleeve thickens and may actually prevent the sleeve from spinning. When the fuser is installed and run in the printer, the grease will heat up and attain proper viscosity.

****** If the printer's display panel reads "REPLACE FUSER KIT", replace

the fuser assembly and perform the following procedure: Press the '▼' button until the display reads 'CONFIGURE DEVICE'. Press the '✓ ' then press the '▼' button until the display says 'RESETS'. Press the '✓' button. Press the '▼' button until the display says 'RESET SUPPLIES' then press the '✓ ' button. Press the '▼' button to select 'FUSER' then press the '✓' button.

About Metrofuser Metrofuser is a leading global innovator, manufacturer and marketer of printer parts, equipment, diagnostics, repair information and systems solutions for professional users performing critical tasks. Products and services include remanufactured laser printer parts, remanufactured printers and printer repair training for HP, Lexmark and Canon brands. The company's customers include office equipment dealerships, online retailers, repair centers and MPS service providers nationwide. Metrofuser has been named to Inc. Magazine’s fastest growing companies five consecutive years. For more information, visit


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