This error indicates that one of the print cores is reading a temperature that is too high. The display will show with which print core a problem has been detected.
Usually, this error is caused by a faulty connection to the temperature sensor in the print core. It could also mean that the print core is not inserted properly while it's hot, heating up, or cooling down. The error may also appear when the print core is removed without following the Change/Unload print core procedure in the touchscreen menu.
The Ultimaker S5 always requires two print cores to be installed. If no print cores are installed, ensure that you install them first.
To find out what is causing the error message, we advise the following steps:
- Check that the print core is installed properly. When inserting it, you should hear an audible click as the print core locks into the slot.
- If the error still occurs, remove it from the print head and examine the PCB at the back of the print core. Dirt and grease from handling the print core can build up on the PCB contact points at the back, leading to connection problems. You can clean the PCB contact points with a cotton swab and some alcohol. To prevent dirt accumulating on the PCB, it is recommended to only hold the print core using the lever.
- Check the contact pins in the print head slot; they might have become dirty as well. Ensure the printer is turned off and disconnected from the power supply, and clean the pins using cotton swabs and alcohol.
- Reinsert the print core, turn the Ultimaker S5 back on and check if the error has disappeared.
If the error continues to appear, you can replace the print core or contact your local service providers for assistance.