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Lexmark C746

Lexmark C746

Firmware update for waste toner performance improvements, false 925.05 stall errors, and reduced printer calibrations

Affected products


This article points to the specific firmware version (LHSC.CM.E247) which addresses the 925.05 error code.

However, the fix is already available in newer firmware versions and it is recommended to upgrade to the latest EC release, should any of these issues occur.

Engine Code Information (.E247)

  • Prevents possible 200.21 errors caused by previous code E246
  • Correction of Aligner motor direction while detecting Waster Toner Bottle (WTB) full/present status (EV 265180)
  • Moreover, added reverse motor function after cover opened and closed (related to the WTB status checking)
  • False 925.05 Fan Stall errors
  • Photoconductor and transfer belt tracking issue when the printer exits Power Saver
  • Number of printer calibrations coming out of sleep mode
  • Waste toner bottle performance improvements

Recommended Firmware Fix

File Information


Available Firmware Filenames

C746, C748 Machine Type: 5026-3xx, 5xxX746, X748 Machine Type: 7526-576, 776

Click here to download latest firmware.

Firmware update recommendations

  1. Check your printer's current code level to see whether the engine code is below the level indicated on the table above. See section below should you be unfamiliar with this procedure.


    The printer cannot be in any type of intervention-requested state such as: paper jam, toner empty, tray empty; or any other warning or error message.

    IMPORTANT! Make sure your organization or business has approved this firmware update. DO NOTattempt to upgrade firmware if the printer has a special printer firmware build or the printer is equipped with a downloadable language emulator.

    Downloadable Language Emulators (DLEs):

    • ImageQuick
    • BarCode
    • PrintCryption
    • Prescribe
  2. Confirm your printer is specifically experiencing the issues referenced in this article.

  3. If you can confirm your issue is one listed, then download and update printer firmware. Otherwise, contact Lexmark Technical Support for further diagnosis.

    After downloading and extracting the flash (.fls) file, select your update method. See section below.

    Large Printer Fleets

    IMPORTANT! Do not update firmware on more than one printer until you have tested and confirmed all other device functions are working properly.

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.FLS File Update Methods

IMPORTANT! Make sure the printer is READY to receive firmware, and do not interrupt the printer's power or data connection during the update process.

All .fls files included in the firmware-download package should be sent to the printer.

Open your internet browser and enter the IP address of the printer. Select Settings >Update Firmware.

Click here for the Firmware update instructions.

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Ways to Determine Printer Firmware Code Levels

Option 1

Print the Menu Settings Page. Do this from the printer's operator panel:




Press the Menu button on the Operator Panel.



next to Reports.


Print the Menu Settings Page.Note: The printer should read ‘Printing Menu Settings Page’ and the menu settings page(s) should print out.


Check the code level under Device Information section on the menu settings pages.

Option 2

Access the printer's Embedded Web Server (EWS). Before you begin, a functional network installation (wired or wireless not a local USB installation) is required for access to the web server of any Lexmark network printer.




Determine the IP address of the print server within the printer/MFP.


Launch your preferred web browser application (e.g., Firefox, Safari, Internet Explorer).


In the address field after the http://, enter the printer's IP address (e.g., or


Click on Reports.


To check for the code level, click on Device Information.

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  • Waste toner bottle motor backup at the end of run to assist with waste toner bottle installation.
  • Fix waste toner box max near full page count bug – same as previous release (change from 250 to 2000 pages), but the count is now stored in case of POR and counted correctly where 245 does not.
  • Fix false 925.05 fan stall errors.
  • Fix TPS sensor temperature reading bug exiting sleep mode during an error like Cover Open
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