"Failure reading a thermocouple"

This article describes the reasons and possible solutions for a “Failure reading a thermocouple” error message. 

Heaters

The Filament Maker uses 4 heaters (labelled H4, H3, H2, and H1 from hopper to nozzle) to melt the material inside the barrel.

Each heater has a thermocouple attached to it, which measures the temperature of each heater. Since not all four thermocouple are the same, we need to remember to refer to them with their associated heaters.

If the error occurs, it is very likely caused by a faulty thermocouple.

filament thickness deviation 2

Thermocouples

To identify the faulty thermocouple, there are some steps we need to take. Firstly, the back panel needs to be removed.

Note

If you are not able to, or are not comfortable doing this, please ask for assistance or Contact Support!

Once you have access to the machine, locate the DevoBoard and the four thermocouple cables connected to it. Pictured below is the DevoBoard with 4 red arrows indicating the 4 red thermocouple cables. They are connected 1 to 4, from left to right.

Devoboard-thermocouple-Medium-min thermocouple replacement cable 2

Identify the faulty thermocouple

Now to identify which thermocouple is faulty.

  1. Turn on the Filament Maker and check the display.

Heaters 1 to 4 will show different temperatures (10-30℃) depending on the environment of the room. If there is a heater that is showing 0℃ that means it is not measuring the temperature accurately, or at all. This is the faulty thermocouple. 

Check the connection

There's a possibility that issue is only a poor cable connection. 

  1. Unplug the faulty thermocouple free from the DevoBoard, and connect it again.

If this works, great! The error message should now disappear. 

Broken thermocouple

If it did not work, there is one more test that can be done.

  1. Swap the thermocouples of the affected heater with any other one.
  2. Check if the other heater also shows 0°C.

If so, it is confirmed that the thermocouple is broken and the machine needs a new one. Unfortunately, it happens from time to time that we might receive some faulty thermocouples in the batch from our supplier. This is something we're currently working to fix.

You can Contact Support to order the new thermocouple and when it is shipped, this guide describes how the old thermocouple must be removed from the heater and how the new one can be installed.

Note:

When ordering a new thermocouple, please specify which thermocouple is broken as the thermocouples for H2, H3, and H4 have the same length thermocouple, however H1 is of a different length and cannot be interchanged with the other three.

Repair

If the replacement thermocouple still didn’t work, unfortunately it is necessary for the machine to be sent back to 3devo HQ for a repair, as the issue is more severe. Please Contact Support, make sure you have your Filament Maker serial number ready, and we can take it from there.