The UltiMaker print cores have a status LED to give a visual indication of what the print core is doing.
The table below explains the different print core statuses and the LED indications:
| Blue | The print core is not in use (idle). It has cooled down to a safe temperature. |
| Blue (pulsing) | The print core is awaiting user input, for example during the Change print core process. |
| Orange | The print core is hot. It has reached the requested target temperature. Do not touch the nozzle or remove the print core. |
| Orange (pulsing) | The print core is hot. It is heating up or cooling down to the requested target temperature. Do not touch the nozzle or remove the print core. |
| White | A print job is in progress. The print core is in use during a print. |
| White (pulsing) | A print job is in progress. The print core is not currently in use, but heating up or cooling down. |
It is always recommended to follow the guided procedures in the menu for loading or unloading a print core. Never remove the print core while the LED status indicates that the print core is in use or hot, as this will cause an error message.
Caution: When certain maintenance actions require interacting with a hot print core (for example, when cleaning the surface of the nozzle), never touch the nozzle with your bare hands. Protective equipment such as thermal gloves is advised.
Note: If you see print core LED behavior that is different from the table above, please update your firmware. Firmware version 8.1 contained a bug that caused the print core in slot 1 to turn green instead of orange while heating and the LED for the print core in slot 2 did not turn on at all. This has been fixed in firmware 8.2.
