The Portrait will shut down and display the Connection failure message whenever it detects an issue with one of its thermistor readings to prevent damages or a potential fire hazard:
| T0 | All-metal hotend is causing the error |  |
| T1 | PTFE hotend is causing the error |  |
 |
Troubleshooting
- Make sure the ambient temperature is within the range specified in the technical specifications (10-30°C).
- Remove the printhead lid and verify that the thermistor is still securely placed in the heater block.
- Check the thermistor cable connector and make sure it isn't loose.
- Turn the printer off using the switch and disconnect the power cable.
- Disconnect the power and thermistor cables.
- Use a Phillips screwdriver to loosen the bolt keeping the Hotend in place and pull it out.
- Remove the silicon sock covering the heat block and loosen the thermistor screw using an Allen wrench.
- Be cautious not to damage the cables when pulling out the thermistor.
- Check the thermistor cartridge and wire for any signs of damage:
Poor condition
Good condition
For instructions on how to replace a thermistor, please see Replacing a Thermistor.warning Too much torque on the thermistor screw will cause the cartridge to deform and damage its sensor, leading to inaccurate readings, and prompt the printer to shut down.
It will also be more difficult to remove the thermistor from the heater block.