Status LED explained (MK4/XL)

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Selected Original Prusa printers are equipped with status LEDs located on the lower edge of the LCD screen. Together there are three physical RGB LEDs. The system will change their color and intensity based on the current scenario. The purpose of this system is to provide helpful visual information to the user.

Compatible printers:

• Original Prusa MK4
• Original Prusa XL

There are several pre-defined scenarios for the LEDs:

• Successful boot
  • Scenario: The boot of the system was assessed as successful.
  • LED response: The LEDs will pulse shortly with a green color.
• Warning
  • Scenario: The printer requires user interaction and then can continue to print (e.g. planned filament change, filament runout, pause in G-code, MMU requires attention, etc.)
  • LED response: The LEDs will pulse in yellow color.
• Critical error
  • Scenario: There is a serious error, and the print job cannot continue. The printer must be fixed in order to work correctly (e.g. Thermal runaway, Preheat error, Max/Min temp, ...)
  • LED response: The LEDs will pulse in red color.
• The print job is in progress
  • Scenario: The printer is currently in the progress of printing the selected G-code.
  • LED response: The LEDs are switched to blue color. 
• The print job is done
  • Scenario: The current print job has finished successfully, the print head is parked and the printer is awaiting the user, to collect the printed object. Please note that the sheet might be still hot! Avoid harming yourself and also give the surface a few moments to cool down to allow easier detachment of the print.
  • LED response: The LEDs are switched to green color.

Use-defined LED statuses

LEDs can be controlled using a G-code M150, you can learn more about it at Marlin FW site.