laserjet pro 200 MFP m276nw : 50.4 50.7 fuser errors (with a good fuser)

[Dan-Kov]

Laserjet pro 200 MFP M276nw with a 50.4 50.7 fuser errors.

Cannot get past the fuser initiation without fuser errors.

(good fuser, tested in a working printer, and tried another fuser

from working printer with same results)

Symptoms are:

Fuser motor runs for 2-3 times longer during poweron (init-phase)

then in a working printer. and does not stop on the fuser rotation sensor position

(unlike working printer, which stops ether directly on sensor or 180 out of phase when off)

And fuser heater relay never clicks on, so no hv to fuser.

(hv board tested as working, swapped in to the good printer)

I am at a loss. As i have no flowcharts for troubleshooting this scenario.

(and would like to fix this printer as we still have lots of supplies,

and printer has low hours)

thanx

dan

[Sneha_01 · Accepted solution]

Hi @Dan-Kov,

Welcome to HP Support Community.

Thank you for posting your query, I will be glad to help you.

It sounds like you're dealing with a persistent fuser error issue on your HP LaserJet Pro 200 MFP M276nw, and you've already done some significant troubleshooting by swapping out fusers and testing components. Here’s a more detailed approach to diagnosing and resolving the issue based on the symptoms and troubleshooting steps you’ve described:

1. Check Fuser Rotation Sensor:

• The fuser rotation sensor might be malfunctioning or misaligned. Check if the sensor is clean and properly aligned. A faulty or dirty sensor can prevent the printer from detecting the fuser’s position correctly.
• Clean the Sensor: Use a soft, lint-free cloth to gently clean the sensor and its surrounding area.
• Ensure there are no obstructions or debris blocking the sensor or its view of the fuser gear.

2. Examine Fuser Motor and Connections:

• Verify that the fuser motor is properly connected and functioning. If the motor is running longer than expected, there might be an issue with the motor or its control circuitry.
• Test the Motor: If possible, test the fuser motor outside the printer to ensure it’s operating correctly.
• Inspect all wiring and connectors associated with the fuser and motor. Loose or damaged connectors can cause communication issues between the fuser and the printer’s control board.

3. Test the Fuser Heater Relay:

• Since the heater relay is not clicking on, it’s essential to verify if the relay is functioning correctly.
• Inspect Connections: Ensure that all connections to the heater relay are secure.
• Test Relay: If possible, test the relay separately or swap it with a known good relay.

4. Evaluate the High Voltage (HV) Board::

• Although you mentioned the HV board was tested in a working printer, ensure that it is functioning correctly in the specific printer model.
• Reinstall HV Board: If you haven’t already, try reinstalling the HV board to ensure all connections are secure.

5. Check Firmware and Calibration::

• Ensure that your printer’s firmware is up-to-date. Firmware updates can resolve various issues, including hardware and sensor malfunctions.
• Check Calibration: Perform a calibration routine if available, as incorrect calibration can sometimes cause fuser errors.

6. Inspect and Test Power Supply:

• Verify that the power supply is providing stable and adequate voltage to all components, including the fuser and HV board.
• Test Voltage: Use a multimeter to check voltage outputs and ensure they meet the printer’s specifications.

7. Check Control Board::

• The printer’s main control board may have a fault. Although this is less common, it can affect various printer functions, including fuser operation.
• Swap Control Boards: If you have access to a known good control board, consider swapping it to see if the issue resolves.

I hope this helps.

Take care and have a good day.

Please mark this post as “Accepted Solution” if the issue is resolved and if you feel this reply was helpful click “Yes”.

Rachel571

HP Support

[Dan-Kov]

Thank you for the reply.

(would be nice to have the same service manual:)

It was the fuser rotation sensor on RM1-8705 board.

Not sure if its the sender diode dying.

Or the sense diode failing.

RPI-579 seems to be the obsolete part (not really stocked anymore).

Will try some close replacements or maybe RM1-8718 sensor circuit

out of an old fuser has 2 of those sensors (if i can find one).

Readings on bad board were

1.83v in sensor unobstructed state

3.00v in sensor obstructed state

Readings on good board were

0.15v in sensor unobstructed state

2.60v in sensor obstructed state

And swapping the good RM1-8705 board resolves the problem.

And swapping the bad RM1-8705 board brings back 50.4 error on the second donor printer.

And now the occasional/repeatable output paper jams as soon as paper hits the last roller

on the fuser is also making sense (as it is a double sensor in almost the same spot)

if one is failing that would cause that issue:)

Thank you very much!

dan

[Sneha_01]

Hi @Dan-Kov 

I'm sending out a private message to assist you with the next course of action. In order to access your private messages, click the private message icon on the upper right corner of your HP Support Community profile, next to your profile Name.

Hope this helps! Keep me posted for further assistance.

Please mark this post as “Accepted Solution” if the issue is resolved and if you feel this reply was helpful click “Yes”.

Rachel571 

HP Support