Chipless Printers
Why Use Epson PX-M840F Firmware Key
– Epson PX-M840F downgrade firmware key: this is required when NON-ORIGINAL ink cartridges are NOT recognized by the printer. This is because printers’ firmware has been updated from the Epson server to the newest firmware where not original ink cartridges are forbidden to be used. In this case, You have to Downgrade firmware back to old.
– When the Epson PX-M840F printer is updated to the new firmware, only genuine ink cartridges are received but not compatible ink cartridges. If we try to insert a compatible ink cartridge into the PX-M840F printer, the printer will warn not to recognize the cartridge and give error messages: Epson PX-M840F Incompatible Ink Cartridge, ink cartridges are not recognized, the ink cartridge is not recognized.
– This article shows how to downgrade the firmware version for Epson PX-M840F. Fix Epson PX-M840F printer error not recognizing external ink cartridges: Epson PX-M840F Incompatible Ink Cartridge, ink cartridges are not recognized, the ink cartridge is not recognized.
– After Downgrade Firmware for Epson PX-M840F printer, the printer can recognize the ink cartridge or we can install a compatible ink cartridge for Epson PX-M840F printer.
– Epson PX-M840F firmware key can fix data recovery mode errors, freezes, and cannot boot into normal mode.
How to downgrade firmware Epson PX-M840F
– Unplug all USB connections to the computer except keyboard, mouse, and Epson PX-M840F printer need to downgrade firmware version.
– Download Downgrade Firmware Epson PX-M840F:
– Free Download Software Downgrade Firmware Epson PX-M840F for Windows: 
– Free Download Software Downgrade Firmware Epson PX-M840F for MAC OS:
Step1.: Install the Wicreset software, then check if the Epson PX-M840F printer is supported with the firmware change feature:
– If supported, we see how to enter Service Mode (Update Mode) for Epson PX-M840F color printer
Step2.: Connect the Epson PX-M840F printer to the computer with a USB cable, then click Change Firmware to see how to enter Service Mode.
– How to enter Service Mode:
Step3.: Select Epson PX-M840F printer to Downgrade Firmware.
Step4.: Select Epson PX-M840F printer then click Update.
Step5.: select Yes to continue.
Step6.: Enter the Epson PX-M840F Firmware Key, then click OK.
Step7.: Wait for the software to automatically downgrade the firmware version for Epson PX-M840F printer.
Step8.: Click OK to complete the firmware version downgrade process for Epson PX-M840F printer.
Step9.: Check the PX-M840F printer firmware after downgrading the version.
Video tutorial to downgrade Epson PX-M840F printer version:
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